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Rapid reperfusion therapy can reduce disability and death in patients with large vessel occlusion strokes (LVOS). It is crucial for emergency medical services to identify LVOS and transport patients directly to a comprehensive stroke center. Our ultimate goal is to develop a non-invasive, accurate, portable, inexpensive, and legally employable in vivo screening system for cerebral artery occlusion. As a first step towards this goal, we propose a method for detecting carotid artery occlusion using pulse wave measurements at the left and right carotid arteries, feature extraction from the pulse waves, and occlusion inference using these features. To meet all of these requirements, we use a piezoelectric sensor. We hypothesize that the difference in the left and right pulse waves caused by reflection is informative, as LVOS is typically caused by unilateral artery occlusion. Therefore, we extracted three features that only represented the physical effects of occlusion based on the difference. For inference, we considered that the logistic regression, a machine learning technique with no complex feature conversion, is a reasonable method for clarifying the contribution of each feature. We tested our hypothesis and conducted an experiment to evaluate the effectiveness and performance of the proposed method. The method achieved a diagnostic accuracy of 0.65, which is higher than the chance level of 0.43. The results indicate that the proposed method has potential for identifying carotid artery occlusions.

This study investigated a method to control neurite outgrowth direction using ultrasound vibration. An ultrasound cell culture dish comprising a glass-bottom culture surface and a glass disc with an ultrasound transducer was fabricated, and undifferentiated neuron-like PC12 cells were grown on the dish as an adherent culture. The 78 kHz resonant concentric flexural vibration mode of the dish was used to quantitatively evaluate the neurite outgrowth direction and length. Time-lapse imaging of cells was performed for 72 h under ultrasound excitation. Unsonicated neurites grew in random directions, whereas neurite outgrowth was circumferentially oriented during ultrasonication in a power-dependent manner. The neurite orientation correlated with the spatial gradient of the ultrasound vibration, implying that neurites tend to grow in directions along which the vibrational amplitude does not change. Ultrasonication with 30 Vpp for 72 h increased the neurite length by 99.7% compared with that observed in unsonicated cells.

SLAMF7 is expressed mainly on multiple myeloma (MM) cells and considered an ideal target for immunotherapeutic approaches. Indeed, elotuzumab, an anti-SLAMF7 antibody, is used for the treatment of MM in combination with immunomodulatory drugs. SLAMF7 is cleaved via unknown mechanisms and detected as a soluble form (sSLAMF7) exclusively in the serum of MM patients; however, little is known about the role of sSLAMF7 in MM biology. In this study, we found that sSLAMF7 enhanced the growth of MM cells via homophilic interaction with surface SLAMF7 and subsequent activation of the SHP-2 and ERK signaling pathways. Elotuzumab suppressed sSLAMF7-induced MM cell growth both in vitro and in vivo. Promoter analyses identified IKZF1 (Ikaros) as a pivotal transcriptional activator of the SLAMF7 gene. Pharmacological targeting of Ikaros by lenalidomide and its analog pomalidomide downregulated SLAMF7 expression and ameliorated the response of MM cells to sSLAMF7. Elotuzumab blocked the growth-promoting function of sSLAMF7 when combined with lenalidomide in a murine xenograft model. Neutralization of sSLAMF7 is a novel antimyeloma mechanism of elotuzumab, which is enhanced by immunomodulatory drugs via downregulation of surface SLAMF7 expression on MM cells. These findings may provide important information for the optimal use of elotuzumab in MM treatment.

Graft failure (GF) remains an obstacle to survival after allogeneic hematopoietic stem cell transplantation. However, differentiating GF from delayed engraftment (DE) can be difficult. Host CD8+ lymphocytes have been reported to mediate graft rejection, but the impact of macrophages on DE or GF is yet to be clarified. Peri-engraftment bone marrow (BM) specimens of 32 adult patients with normal engraftment, DE or GF were retrospectively evaluated to identify the potential associations of CD163+ macrophage and CD8+ lymphocyte infiltration into BM. The macrophage or CD8+ lymphocyte number/total nucleated cell number was defined as the Mac ratio and CD8 ratio, respectively. Both DE and GF groups had significantly higher Mac ratios at day 14 than the normal group (P

The experimental investigation of an optical fiber Bragg grating (FBG) sensor for biomedical application is described. The FBG sensor can be used to measure sound pressure and temperature rise simultaneously in biological tissues exposed to ultrasound. The theoretical maximum values that can be measured with the FBG sensor are 73.0 MPa and 30 °C. In this study, measurement of sound pressure up to 5 MPa was performed at an ultrasound frequency of 2 MHz. A maximum temperature change of 6 °C was measured in a tissue-mimicking material. Values yielded by the FBG sensor agreed with those measured using a thermocouple and a hydrophone. Since this sensor is used to monitor the sound pressure and temperature simultaneously, it can also be used for industrial applications, such as ultrasonic cleaning of semiconductors under controlled temperatures.

Several clinical trials have demonstrated the effectiveness of bortezomib in combination with various anti-myeloma agents; however, no definitive information is available regarding drugs best suited for use in combination with bortezomib. Using isobologram analysis, we investigated the combined effects of bortezomib with four key anti-myeloma drugs (melphalan, cyclophosphamide, doxorubicin and lenalidomide), which represent components of major bortezomib-based regimens with corticosteroids, in three myeloma cell lines (U266, RPMI8226 and KMS-12BM) under various conditions. Melphalan showed the best performance with bortezomib under all culture conditions tested (liquid culture, on fibronectin-coated plates, and co-culture with bone marrow stromal cells), whereas cyclophosphamide was antagonistic with bortezomib especially in the presence of stromal cells. Doxorubicin showed additive effects under stroma-free conditions and in contact with fibronectin, but was rather antagonistic in the presence of stromal cells. In contrast, lenalidomide exerted the most favorable effect with bortezomib in contact with stromal cells. Consistent with these results, caspase-3 was activated more strongly by melphalan than by other agents in combination with bortezomib. Moreover, bortezomib-induced up-regulation of CHOP was readily enhanced by lenalidomide in contact with stromal cells. The present findings may provide fundamental information for the selection of bortezomib-based regimens for myeloma patients.

The Notch signaling pathway has been recognized as a key factor for the pathogenesis of T-cell acute lymphoblastic leukemia (T-ALL), because of the high incidence of activating mutations of Notch1. Notch inhibition could serve as a new treatment strategy for T-ALL; however, the attempts to perturb Notch signaling pathways have been unsuccessful so far. In this study, we found that proteasome inhibitors exert cytotoxic effects on T-ALL cells with constitutive activation of Notch1 to a similar extent as myeloma cells. The proteasome inhibitor bortezomib repressed the transcription of Notch1 and downstream effectors including Hes1, GATA3, RUNX3 and nuclear factor-κB (NF-κB) (p65 and p50), coincided with downregulation of the major transactivator Sp1 and its dissociation from Notch1 promoter. Overexpression of the Notch1 intracellular domain (NICD) significantly ameliorated bortezomib-induced cytotoxicity against T-ALL cells. Drug combination studies revealed that bortezomib showed synergistic or additive effects with key drugs for the treatment of T-ALL such as dexamethasone (DEX), doxorubicin and cyclophosphamide, which were readily abolished by NICD overexpression. The synergy of bortezomib and DEX was confirmed in vivo using a murine xenograft model. Our findings provide a molecular basis and rationale for the inclusion of proteasome inhibitors in treatment strategies for T-ALL.

The multiple Dirichlet-to-Neumann (DtN) boundary condition has been derived by Grote and Kirsch (J Comput Phys 201:630–650, 2004) to numerically solve multiple scattering problems. An a priori error estimate is established for finite element methods applied to the Helmholtz problem with the multiple DtN boundary condition. The error estimates account for the effects of truncation of infinite Fourier series representing the multiple DtN boundary condition as well as of discretization of the finite element method.

Iron overload is a common complication in allogeneic hematopoietic cell transplantation (HCT). We studied the prevalence of iron overload using serum ferritin from 122 allogeneic HCT survivors who had survived a median of 1259 (range 134–4261) days. We also quantified iron overload by determining non-transferrin-bound iron (NTBI), which reflects iron overload more directly than ferritin, and compared the results with those of the ferritin assay. Fifty-two patients (43 %) showed hyperferritinemia (HF) (serum ferritin >1000 ng/mL), and there was a moderate correlation between serum ferritin and the number of transfused red blood cell units (ρ = 0.71). In multivariate analyses, HF was a significant risk factor for liver dysfunction (P = 0.0001) and diabetes (P = 0.02), and was related to a lesser extent with performance status (P = 0.08). There was a significant correlation between serum ferritin and NTBI (ρ = 0.59); however, the association of NTBI with these outcomes was weaker than that of serum ferritin. In conclusion, serum ferritin is a good surrogate marker of iron overload after allogeneic HCT, and reflects organ damage more accurately than NTBI.

The effects of macrophage activation on the outcome of allogeneic hematopoietic SCT (allo-HSCT) have yet to be fully examined. A total of 70 adult patients who received a first allo-HSCT for hematological diseases were studied. We counted the number of hemophagocytic cells in BM clot sections on day +14±7, and analyzed its impact on subsequent outcome. In all, 23 patients were diagnosed as having increased numbers of hemophagocytic cells (HP group), whereas 47 were not (non-HP group). The HP group was not associated with an increased incidence of acute or chronic GVHD, but was associated with worse hematopoietic recovery than the non-HP group. The 2-year OS for the HP group and the non-HP group was 30 and 65% (P

The aim of this study was realization of a broadband measurement system that is capable of effectively carrying out a frequency compound method. In the present method, the secondary wave components of difference and sum frequencies are generated along with the higher harmonic components through the nonlinear interaction of two-frequency ultrasound. A multiple-frequency beam is generated together with the initially radiated frequency components. For the structure of a transducer capable of simultaneously radiating two sound waves with different frequencies, a coaxial arrangement of a circular-disc piezoelectric transducer and a ring piezoelectric transducer was designed. The radiating frequencies chosen were 2 and 8 MHz. In addition to the 4-MHz second harmonic sound of the 2-MHz primary sound, sounds of the 6-MHz difference frequency and the 10-MHz sum frequency can be generated. By measuring the acoustic pressure distribution, the formation of a multiple-frequency beam was confirmed. The signal-to-noise ratio in an agar-gel phantom image was increased by 5–6 dB with application of the frequency compound method. The validity of the proposed method was demonstrated through the generation of a human finger image. Further, it was found that the influence of the Doppler effect was small enough that almost all the secondary waves were attributable to the nonlinear propagation of sounds. A multiple-frequency sound beam was realized by radiating a two-frequency sound. The effectiveness of the presented method was demonstrated through actual imaging.

The exterior Helmholtz problem is solved by a controllability method with a new artificial boundary condition for a time-periodic wave equation. The condition uses the Dirichlet-to-Neumann operator associated with the Helmholtz problem. A semi-discrete problem is derived for the time-periodic wave equation, and a necessary and sufficient condition is proved for the uniqueness of the discrete problem. A typical example where the condition is satisfied is shown. Some numerical examples are also presented.

We consider the eigenvalue problem of the linear water wave in a water region with a reentrant corner. When approximate solutions of the problem are obtained by means of standard finite element methods, it often happens that the rates of convergence for the approximate solutions are slow. To improve the behavior of the rates of convergence, we propose a numerical method.