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Abstract This study investigated a technique for controlling the orientation of C2C12-derived myotube cells using ultrasonication for future clinical applications of cultured skeletal muscle tissues. An ultrasonicating cell culture dish, comprising a plastic-bottomed culture dish and a circular glass plate (diameter, 35 mm; thickness, 1.1 mm) attached to an annular piezoelectric ultrasonic transducer (inner diameter, 10 mm; outer diameter, 20 mm; thickness, 1 mm), was constructed. A concentric resonant vibrational mode at 89 kHz was generated on the bottom of the dish, and the orientations of myotube cells were quantitatively evaluated using two-dimensional Fourier transform analysis of phase contrast microscopy images captured over a 14 × 10 mm2 area at the center of the dish. Unsonicated myotube cells grew in random directions, but ultrasonication aligned them circumferentially in the culture dish. The timing of treatment was important, with ultrasonication for 48 h before differentiation having a greater impact on myotube orientation than ultrasonication after differentiation. A larger ultrasonic vibration, with an amplitude of over 20 Vpp, resulted in significantly smaller angles of deviation in the circumferential direction than the control. Ultrasonication enhanced the expression of differentiation-related genes and the formation of aligned myotubes, suggesting that it promotes differentiation of C2C12 cells into myotubes.

Abstract Conventional light diffusers have periodic surface profiles, periodic refractive index distributions, or light scattering layers containing colloids. In all such structures the optical directivity of the light diffuser is cannot typically be controlled. Here we propose an electrically tunable light diffuser based on the application of ultrasound to a nematic liquid crystal (LC) material. The ultrasonic LC diffuser consists of an LC layer sandwiched by two glass discs and an ultrasonic transducer. The electrodes of the transducer are divided in a circumferential direction so that a resonant non-coaxial flexural vibration mode can be generated on the diffuser by controlling the electrical input signals. A continuous reversed-phase sinusoidal electric signal to the transducer generates the non-coaxial resonant flexural vibration mode on the glass disc, inducing an acoustic radiation force acting on the boundary between the LC layer and glass discs. This effect changes the molecular orientation of the LC and the transmitted light distribution. The diffusion angle of the transmitted light depends on the input voltage amplitude, and the diffusion angle was maximized at 16.0 V. The vibrational distribution and the diffusion directivity could be rotated by adjusting the input voltages to different electrodes, meaning that an ultrasonic LC diffuser with a thin structure and no moving mechanical parts provided a tunable light-diffusing functionality with rotatable directivity.

Abstract Background The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has had a profound global impact, with millions of confirmed cases and deaths worldwide. While most cases are mild, a subset progresses to severe respiratory complications and death, with factors such as thromboembolism, age, and underlying health conditions increasing the risk. Vascular endothelial damage has been implicated in severe outcomes, but specific biomarkers remain elusive. This study investigated syndecan-1 (SDC-1), a marker of endothelial damage, as a potential prognostic factor for COVID-19, focusing on the Japanese population, which is known for its aging demographics and high prevalence of comorbidities. Methods A multicenter retrospective study of COVID-19 patients in Fukushima Prefecture in Japan who were admitted between February 2020 and August 2021 was conducted. SDC-1 levels were measured along with other clinical and laboratory parameters. Outcomes including thrombosis, 28-day survival, and disease severity were assessed, and disease severity was categorized according to established guidelines. Results SDC-1 levels were correlated with disease severity. Patients who died from COVID-19 had greater SDC-1 levels than survivors, and the area under the receiver operating characteristic curve (AUC) analysis suggested the potential of the SDC-1 level as a predictor of mortality (AUC 0.714). K‒M analysis also revealed a significant difference in survival based on an SDC-1 cutoff of 10.65 ng/mL. Discussion This study suggested that SDC-1 may serve as a valuable biomarker for assessing COVID-19 severity and predicting mortality within 28 days of hospitalization, particularly in the Japanese population. However, further investigations are required to assess longitudinal changes in SDC-1 levels, validate its predictive value for long-term survival, and consider its applicability to new viral variants. Conclusions SDC-1 is emerging as a potential biomarker for assessing the severity and life expectancy of COVID-19 in the Japanese population, offering promise for improved risk stratification and patient management in the ongoing fight against the virus.

Abstract Microbubbles have potential applications as drug and gene carriers, and drug release can be triggered by externally applied ultrasound irradiation while inside blood vessels. Desorption of molecules forming the microbubble shell can be observed under ultrasound irradiation of a single isolated microbubble, and the volume of desorbed molecules can be quantitatively estimated from the contact angle between the bubble and a glass plate. Microbubbles composed of a 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) shell and a poorly-soluble gas are created. When the microbubbles are exposed to a pulsed ultrasound, the contact angles increase dramatically; the percentage of DMPC molecules desorbed from the bubble surface reaches 70%. Vibration of a single bubble in the radial direction is measured using a laser Doppler vibrometer. The relationship between the vibrational characteristics and the amount of molecular desorption reveals that a larger vibrational amplitude of the bubble around the resonance size induces a larger amount of molecular desorption. These results support the possibility of controlling molecular desorption with pulsed ultrasound.

Abstract 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.

Abstract Paroxysmal cold hemoglobinuria (PCH) is an extremely rare subtype of autoimmune hemolytic anemia (AIHA) in adults. PCH is caused by the biphasic Donath–Landsteiner (DL) antibody which fixes complement to red blood cells at low temperatures and dissociates at warmer temperatures, leading to complement‐mediated intravascular hemolysis. Autoimmune hematological disorders including AIHA and immune thrombocytopenia have been reported to develop following the mRNA COVID‐19 vaccination. However, PCH developing subsequent to mRNA vaccination has never been reported. We report a 59‐year‐old male who developed PCH approximately a month after his second mRNA COVID‐19 vaccination.

Abstract 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.

Abstract We used the eXtreme Gradient Boosting algorithm, an optimized gradient boosting machine learning library, and established a model to predict events in Philadelphia chromosome-positive acute lymphoblastic leukemia using a machine learning-aided method. A model was constructed using a training set (80%) and prediction was tested using a test set (20%). According to the feature importance score, BCR-ABL lineage, polymerase chain reaction value, age, and white blood cell count were identified as important features. These features were also confirmed by the permutation feature importance for the prediction using the test set. Both event-free survival and overall survival were clearly stratified according to risk groups categorized using these features: 80 and 100% in low risk (two or less factors), 42 and 47% in intermediate risk (three factors), and 0 and 10% in high risk (four factors) at 4 years. Machine learning-aided analysis was able to identify clinically useful prognostic factors using data from a relatively small number of patients.

BackgroundRecently, various blood cell lineages expressing the BCR-ABL fusion gene in Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia (ALL) have been reported. However, the biological and clinical significance of these BCR-ABL lineages has not been established; therefore, we aimed to clarify the impacts of these different BCR-ABL-expressing lineages.PatientsMulti-lineage BCR-ABL expression (multi-Ph) was defined as BCR-ABL expression outside of the B-lineage compartment, as determined by fluorescence in situ hybridization (FISH) in peripheral blood neutrophils and bone marrow clots, and flow cytometry-sorted polymerase chain reaction (PCR). We analyzed IKZF1 deletion patterns by PCR, examined gene expression profiles using RNA sequencing, and compared treatment outcomes across different BCR-ABL-expressing lineages.ResultsAmong the 21 multi-Ph patients in our 59-patient cohort (36%), BCR-ABL expression was detected at the multipotential progenitor level. However, no IKZF1 deletion patterns or gene expression profiles were identified that were specific for multi-Ph. However, multi-Ph patients were found to have better survival rates than patients with uni-lineage BCR-ABL expression [event-free survival (EFS): 74 vs. 33%, P = 0.01; overall survival (OS): 79 vs. 44% at 4 years, P = 0.01]. In multivariate analyses, multi-Ph was identified as a good prognostic factor for both EFS and OS.ConclusionWe confirmed that more than one-third of Ph+ALL patients could be classified as mutli-Ph. Although no specific molecular characteristics were identified for multi-Ph, this phenotype was associated with better treatment outcomes.

While the low-intensity pulsed ultrasound technique has proved useful for healing of bone fractures, the ultrasound healing mechanism is not yet understood. To understand the initial physical effects of the ultrasound irradiation process on bone, we have studied the anisotropic piezoelectric properties of bone in the MHz range. Bone is known to be composed of collagen and hydroxyapatite (HAp) and shows strong elastic anisotropy. In this study, the effects of HAp on the piezoelectricity were investigated experimentally. To remove the HAp crystallites from the bovine cortical bone, demineralization was performed using ethylene diamine tetra-acetic acid (EDTA) solutions. To investigate the piezoelectricity, we have fabricated ultrasound transducers using the cortical bone or demineralized cortical bone. The induced electrical potentials due to the piezoelectricity were observed as the output of these transducers under pulsed ultrasound irradiation in the MHz range. The cortical bone transducer (before mineralization) showed anisotropic piezoelectric behavior. When the ultrasound irradiation was applied normal to the transducer surface, the observed induced electrical potentials had minimum values. The potential increased under off-axis ultrasound irradiation with changes in polarization. In the demineralized bone transducer case, however, the anisotropic behavior was not observed in the induced electrical potentials. These results therefore indicate that the HAp crystallites affect the piezoelectric characteristics of bone.

Hydroxyapatite (HAp) is compatible with bone tissue and is used mainly as a bone prosthetic material, especially as the coating of implants. Oriented HAp film is expected to be a high-quality epitaxial scaffold of the neonatal bone. To fabricate highly oriented HAp thin films via the conventional plasma process, we deposited the HAp film on a Ti coated silica glass substrate using RF magnetron sputtering in low substrate temperature conditions. The X-ray diffraction pattern of the film sample consisted of an intense (002) peak, corresponding to the highly oriented HAp. The (002) peak in XRD diagrams can be attributed either to the monoclinic phase or the hexagonal phase. Pole figure analysis showed that the (002) plane grew parallel to the surface of the substrate, without inclination. Transmission Electron Microscope analysis also showed the fabrication of aligned HAp crystallites. The selected area diffraction patterns indicated the existence of monoclinic phase. The existence of hexagonal phase could not be judged. These results indicate the uniaxial films fabricated by this technique enable to be the epitaxial scaffold of the neonatal bone. This scaffold can be expected to promote connection with the surrounding bone tissue and recovery of the dynamic characteristics of the bone.

Regenerating islet-derived protein 3 alpha (REG3A) is a biomarker of lower gastrointestinal graft-versus-host disease (GVHD); however, the biological role of REG3A in the pathophysiology of GVHD is not understood. Here, we examined the association between a single nucleotide polymorphism in the REG3A gene, rs7588571, which is located upstream and within 2 kb of the REG3A gene, and transplant outcomes including the incidence of GVHD. The study population consisted of 126 adult Japanese patients who had undergone bone marrow transplantation from a HLA-matched sibling. There was no association between rs7588571 polymorphism and the incidence of acute GVHD. However, a significantly higher incidence of extensive chronic GVHD was observed in patients with the rs7588571 non-GG genotype than in those with the GG genotype (Odds ratio 2.6; 95% confidence interval, 1.1-6.0; P = 0.029). Semi-quantitative reverse transcription PCR demonstrated that the rs7588571 non-GG genotype exhibited a significantly lower REG3A mRNA expression level than the GG genotype (P = 0.032), and Western blot analysis demonstrated that the rs7588571 non-GG genotype exhibited a trend toward lower REG3A protein expression level than the GG genotype (P = 0.053). Since REG proteins have several activities that function to control intestinal microbiota, and since intestinal dysbiosis is in part responsible for the development of GVHD, our findings lead to the novel concept that REG3A could have some protective effect in the pathogenesis of GVHD through the regulation of gut microbiota.

Background: Inhaled corticosteroids enhance airway epithelial barrier integrity. However, the mechanism by which they accomplish this is unclear. Therefore, we investigated steroid-inducible genes and signaling pathways that were involved in enhancing airway epithelial barrier integrity. Methods: A human bronchial epithelial cell line (16HBE cells) was cultured with 10−6 M dexamethasone (DEX) for 3 days to enhance epithelial barrier integrity. After measuring transepithelial electrical resistance (TER) and paracellular permeability, we extracted total RNA from 16HBE cells and performed microarray and pathway analysis. After we identified candidate genes and a canonical pathway, we measured TER and immunostained for tight junction (TJ) and adherent junction (AJ) proteins in cells that had been transfected with specific small interfering RNAs (siRNAs) for these genes. Results: We identified a nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated oxidative stress response pathway which was primarily involved in the steroid-induced enhancement of airway epithelial barrier integrity. Transfecting cells with Nrf2 specific siRNA reduced the steroid-induced enhancement of airway epithelial barrier integrity and the accumulation of TJ and AJ proteins at sites of cell–cell contact. Moreover, based on pathway analysis, aldehyde oxidase 1 (AOX1) was identified as a downstream enzyme of Nrf2. Transfecting cells with AOX1-specific siRNA also reduced the steroid-induced enhancement of airway epithelial barrier integrity. Conclusions: Our results indicated that the Nrf2/AOX1 pathway was important for enhancing airway epithelial barrier integrity. Because the airway epithelium of asthmatics is susceptible to reduced barrier integrity, this pathway might be a new therapeutic target for asthma.

Background: Allergic sensitization is a key step in the pathogenesis of asthma. However, little is known about the molecules that are critical regulators for establishing allergic sensitization of the airway. Thus, we conducted global gene expression profiling to identify candidate genes and signaling pathways involved in house dust mite (HDM)-induced allergic sensitization in the murine airway. Methods: We sensitized and challenged mice with HDM or saline as a control through the airway on days 1 and 8. We evaluated eosinophilia in bronchoalveolar lavage fluid (BALF), airway inflammation, and mucus production on days 7 and 14. We extracted total RNA from lung tissues of HDM- and saline-sensitized mice on days 7 and 14. Microarray analyses were performed to identify up-regulated genes in the lungs of HDM-sensitized mice compared to the control mice. Data analyses were performed using GeneSpring software and gene networks were generated using Ingenuity Pathways Analysis (IPA). Results: We identified 50 HDM-mediated, stepwise up-regulated genes in response to allergic sensitization and amplification of allergic airway inflammation. The highest expressed gene was myeloid differentiation-2 (MD-2), a lipopolysaccharide (LPS)-binding component of Toll-like receptor (TLR) 4 signaling complex. MD-2 protein was expressed in lung vascular endothelial cells and was increased in the serum of HDM-sensitized mice, but not in the control mice. Conclusions: Our data suggest MD-2 is a critical regulator of the establishment of allergic airway sensitization to HDM in mice. Serum MD-2 may represent a potential biomarker for the amplification of allergic sensitization and allergic inflammation.

Bendamustine has shown considerable clinical activity against indolent lymphoid malignancies as a single agent or in combination with rituximab, but combination with additional anti-cancer drugs may be required for refractory and/or relapsed cases as well as other intractable tumors. In this study, we attempted to determine suitable anti-cancer drugs to be combined with bendamustine for the treatment of mantle cell lymphoma, diffuse large B-cell lymphoma, aggressive lymphomas and multiple myeloma, all of which are relatively resistant to this drug, and investigated the mechanisms underlying synergism. Isobologram analysis revealed that bendamustine had synergistic effects with alkylating agents (4-hydroperoxy-cyclophosphamide, chlorambucil and melphalan) and pyrimidine analogues (cytosine arabinoside, gemcitabine and decitabine) in HBL-2, B104, Namalwa and U266 cell lines, which represent the above entities respectively. In cell cycle analysis, bendamustine induced late S-phase arrest, which was enhanced by 4-hydroperoxy-cyclophosphamide, and potentiated early S-phase arrest by cytosine arabinoside (Ara-C), followed by a robust increase in the size of sub-G1 fractions. Bendamustine was able to elicit DNA damage response and subsequent apoptosis faster and with shorter exposure than other alkylating agents due to rapid intracellular incorporation via equilibrative nucleoside transporters (ENTs). Furthermore, bendamustine increased the expression of ENT1 at both mRNA and protein levels and enhanced the uptake of Ara-C and subsequent increase in Ara-C triphosphate (Ara-CTP) in HBL-2 cells to an extent comparable with the purine analog fludarabine. These purine analog-like properties of bendamustine may underlie favorable combinations with other alkylators and pyrimidine analogues. Our findings may provide a theoretical basis for the development of more effective bendamustine-based combination therapies.

Methods for controlling the periodic molecular orientation of liquid crystals using ultrasound vibrations and estimating the orientational direction are proposed. An ultrasonic liquid crystal cell was used, consisting of a liquid crystal layer sandwiched by two glass plates fitted with piezoelectric ultrasound transducers. The transmitted light intensity distribution through the cell was measured by changing the polarization direction to investigate the orientation direction of the liquid crystal molecules. The transmitted light distributions changed periodically owing to the flexural vibration of the cell at resonance frequencies of 43.9 and 70.7 kHz. The orientational direction of the liquid crystal molecules correlated with the vibrational distribution of the glass substrates, and the molecular orientation was changed periodically by the acoustic radiation force. The interval and intensity of the transmitted light could be controlled by the driving frequency and voltage amplitude, respectively. [ABSTRACT FROM AUTHOR]

The computationally predicted presence of two structurally distinct minima in the first triplet excited (T1) state of 2-thiouracil (2TU) is substantiated by sub-picosecond transient vibrational absorption spectroscopy (TVAS) in deuterated acetonitrile solution. Following 300 nm ultraviolet excitation to the second singlet excited state of 2TU, a transient infrared absorption band centered at 1643 cm-1 is observed within our minimum time resolution of 0.3 ps. It is assigned either to 2TU molecules in the S1 state or to vibrationally hot T1-state molecules, with the latter assignment more consistent with recent computational and experimental studies. The 1643 cm-1 band decays with a time constant of 7.2 ± 0.8 ps, and there is corresponding growth of several further bands centered at 1234, 1410, 1424, 1443, 1511, 1626, and 1660 cm-1 which show no decline in intensity over the 1 ns time limit of our measurements. These spectral features are assigned to two different conformations of 2TU, corresponding to separate energy minima on the T1-state potential energy surface, on the basis of their extended lifetimes, computed infrared frequencies, and the observed quenching of the bands by addition of styrene. Corresponding measurements for the 4-thiouracil (4TU) isomer show sub-picosecond population of the T1 state, which vibrationally cools with a time constant of 5.2 ± 0.6 ps. However, TVAS measurements in the carbonyl stretching region do not distinguish the two computed T1-state conformers of 4TU because of the similarity of their vibrational frequencies. [ABSTRACT FROM AUTHOR]

Alterations in chromatin modifications, such as histone methylation, have been suggested as mediating chemotherapy resistance in several cancer types; therefore, elucidation of the epigenetic mechanisms that underlie drug resistance may greatly contribute to the advancement of cancer therapies. In the present study, we identified histone H3-lysine 27 (H3K27) as a critical residue for epigenetic modification in multiple myeloma. We determined that abrogation of drug-induced H3K27 hypermethylation is associated with cell adhesion-mediated drug resistance (CAM-DR), which is the most important form of drug resistance, using a coculture system to evaluate stroma cell adhesion-dependent alterations in multiple myeloma cells. Cell adhesion counteracted anticancer drug-induced hypermethylation of H3K27 via inactivating phosphorylation of the transcription regulator EZH2 at serine 21, leading to the sustained expression of antiapoptotic genes, including IGF1, B cell CLL/lymphoma 2 (BCL2), and hypoxia inducible factor 1, α subunit (HIF1A). Pharmacological and genetic inhibition of the IGF-1R/PI3K/AKT pathway reversed CAM-DR by promoting EZH2 dephosphorylation and H3K27 hypermethylation both in vitro and in refractory murine myeloma models. Together, our findings identify and characterize an epigenetic mechanism that underlies CAM-DR and suggest that kinase inhibitors to counteract EZH2 phosphorylation should be included in combination chemotherapy to increase therapeutic index. [ABSTRACT FROM AUTHOR]

Recent investigations indicate that epigenetic regulators act at the initial step of myeloid leukemogenesis by forming preleukemic hematopoietic stem cells (HSCs), which possess the increased self-renewal potential but retain multidifferentiation ability, and synergize with genetic abnormalities in later stages to develop full-blown acute myeloid leukemias. However, it is still unknown whether this theory is applicable to other malignancies. In this study, we demonstrate that lysine-specific demethylase 1 (LSD1) overexpression is a founder abnormality for the development of T-cell lymphoblastic leukemia/lymphoma (T-LBL) using LSD1 transgenic mice. LSD1 expression is tightly regulated via alternative splicing and transcriptional repression in HSCs and is altered in most leukemias, especially T-LBL. Overexpression of the shortest isoform of LSD1, which is specifically repressed in quiescent HSCs and demethylates histone H3K9 more efficiently than other isoforms, increases self-renewal potential via up-regulation of the HoxA family but retains multidifferentiation ability with a skewed differentiation to T-cell lineages at transcriptome levels in HSCs. Transgenic mice overexpressing LSD1 in HSCs did not show obvious abnormalities but developed T-LBL at very high frequency after γ-irradiation. LSD1 overexpression appears to be the first hit in T-cell leukemogenesis and provides an insight into novel strategies for early diagnosis and effective treatment of the disease. [ABSTRACT FROM AUTHOR]

The direct finite-difference fluid simulation of acoustic streaming on a fine-meshed three-dimensional model using a graphics processing unit (GPU)-based calculation array is discussed. Airflows are induced by an acoustic traveling wave when an intense sound field is generated in a gap between a bending transducer and a reflector. The calculation results showed good agreement with measurements in a pressure distribution. Several flow vortices were observed near the boundary layer of the reflector and the transducer, which have often been observed near the boundary of acoustic tubes, but have not been observed in previous calculations for this type of ultrasonic air pump. [ABSTRACT FROM AUTHOR]

Abstract  If a pipe end is faced at a piston-vibrating surface with a small gap in liquid, the liquid is suctioned into the pipe. The present ultrasonic pump is based on this phenomenon to induce flow. For a low-profile configuration, we introduce a 30-mm-diameter bending disk driven by a ring-shaped PZT element bonded on the back of the disk. The disk vibrator is softly supported by frames via O-rings at its circumference, and is worked at the fundamental resonance frequency of 19 kHz of the bending mode. A pipe is installed perpendicularly to the center of the disk vibrator with a small gap. To improve the pump performance, we seek for the optimum vibration distribution of the disk vibrator. When the thickness around the disk center becomes large, the shape of the vibration distribution near the center approaches to a piston vibrator. If the flatness of the vibration distribution is defined as the vibration amplitude just under the pipe edge divided by the vibration amplitude at the disk center, it is 92.0% for the original bending disk. The flatness of the new design became 98.1% as a result of the optimization of the thickness profile of the disk. The pump pressure became high as the flatness became large when the gap size was small enough. The maximum pump pressure of 20.6 kPa was achieved when the vibration velocity at the disk center was 1.0 m/s and the gap size was 10 μm, while the maximum flow rate of 22.5 ml/min. was obtained with the input electrical power of 3.8 W. [ABSTRACT FROM AUTHOR]

Bortezomib therapy is now indispensable for multiple myeloma, but is associated with patient inconvenience due to intravenous injection and emerging drug resistance. The development of orally active proteasome inhibitors with distinct mechanisms of action is therefore eagerly awaited. Previously, we identified homopiperazine derivatives as a novel class of proteasome inhibitors with a different mode of proteasome binding from bortezomib. In this study, we show that K-7174, one of proteasome inhibitory homopiperazine derivatives, exhibits a therapeutic effect, which is stronger when administered orally than intravenously, without obvious side effects in a murine myeloma model. Moreover, K-7174 kills bortezomib-resistant myeloma cells carrying a5-subunit mutation in vivo and primary cells from a patient resistant to bortezomib. K-7174 induces transcriptional repression of class I histone deacetylases (HDAC1, -2, and -3) via caspase-8-dependent degradation of Sp1, the most potent transactivator of class I HDAC genes. HDAC1 overexpression ameliorates the cytotoxic effect of K-7174 and abrogates histone hyperacetylation without affecting the accumulation of ubiquitinated proteins in K-7174-treated myeloma cells. Conversely, HDAC inhibitors enhance the activity of K-7174 with an increase in histone acetylation. These results suggest that class I HDACs are critical targets of K-7174-induced cytotoxicity. It is highly anticipated that K-7174 increases the tolerability and convenience of patients by oral administration and has the clinical utility in overcoming bortezomib resistance as a single agent or in combination with HDAC inhibitors. [ABSTRACT FROM AUTHOR]