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Biomedical subjects

Hideki Tanaka

Publications and source records attributed to Hideki Tanaka.

At least 19 recordsLinked to original sources
PubMed2026

Amivantamab in Recurrent/Metastatic Head and Neck Squamous Cell Cancer After Checkpoint Inhibitor and Chemotherapy: Pivotal Results From the Phase Ib/II OrigAMI-4 Study.

Single-agent paclitaxel or cetuximab after immune checkpoint inhibitor (ICI) and chemotherapy demonstrated objective response rates (ORRs) of 21%-24% in recurrent/metastatic (R/M) head/neck squamous cell cancer (HNSCC). Epidermal growth factor receptor (EGFR) and MET are overexpressed in R/M HNSCC. Amivantamab, an EGFR-MET bispecific antibody, may be a rational treatment. Cohort 1 of OrigAMI-4 (ClinicalTrials.gov identifier: NCT06385080) evaluated subcutaneous amivantamab administered every 3 weeks in participants with non-human papillomavirus R/M HNSCC after PD-(L)1 inhibitor and platinum-based chemotherapy. Prior anti-EGFR therapy and p16-positive oropharyngeal cancer were exclusionary. The primary end point was RECIST v1.1 ORR. Secondary end points included duration of response (DoR), progression-free survival (PFS), overall survival (OS), and safety. In 102 participants, blinded independent central review‑assessed ORR was 42% (95% CI, 32 to 52); the complete response rate was 15%. Median DoR was not reached (NR; 95% CI, 6.9 to NR); 56% of responses lasted ≥6 months. Investigator-assessed ORR was 47% (95% CI, 37 to 57). At a median follow-up of 11.8 months (range, 1.1-21.9), median PFS and OS were 6.8 months (95% CI, 5.2 to 8.3) and 12.5 months (95% CI, 10.2 to 16.8), respectively. Adverse events were consistent with previous experience with no new safety signals. Treatment-related discontinuations were low (8%). Amivantamab demonstrated greater antitumor activity in participants previously exposed to ICI and chemotherapy than has been reported for paclitaxel or cetuximab.

Humans↗
PubMed2006

Coordination symmetry-dependent structure restoration function of one-dimensional MOFs by molecular respiration.

One-dimensional metal-organic compounds with cis, trans symmetry-controlled counter anions were synthesized (cis compound {[Cu(azpy)(H2O)2(OTs)2]*2H2O*(acetone)} (1) and trans compound {[Cu(H2O)4Cu(azpy)2(OTs)2(H2O)2]*2(OTs)*2H2O*2EtOH} (2)). Only 2, having trans conformation, exhibited a complete structure-restoration effect with a mechanism involving layering of molecular "bricks" of water and solvent molecules.

Journal Article↗
PubMed2006

RBM band shift-evidenced dispersion mechanism of single-wall carbon nanotube bundles with NaDDBS.

The dispersion process of single-wall carbon nanotube (SWNT) by using sodium dodecylbenzene sulfonate (NaDDBS) was studied by means of surface tension measurements, ultraviolet-visible (UV-Vis) spectroscopy, scanning electron microscopy (SEM), and transmission electron spectroscopy (TEM). The critical micelle concentration (CMC) and the concentration where the surface tension begins to drop increase by the presence of SWNT. The isotherm of NaDDBS amount adsorbed on SWNT shows the plateau region at 0.2-6 mM and the saturated region above 40 mM. The external surface of SWNT bundle is fully covered with adsorbed NaDDBS at the plateau region, showing that SWNTs can be dispersed with the bundle form. On the other hand, SWNTs are dispersed in individual tubes at the saturated region, where the adsorption amount corresponds to coating of individual tube surfaces with NaDDBS. This dispersion state was confirmed by SEM and TEM observations. The effect of the dispersion state of SWNTs on radial breathing mode in Raman spectrum gave inherent peak shifts, being the in situ evidences on the step-wise dispersion mechanism of the SWNT bundle to the individual tubes.

Journal Article↗
PubMed2006

Expression of growth hormone family and growth hormone receptor during early development in the Japanese eel (Anguilla japonica).

In a previous study, we identified cDNAs encoding the growth hormone receptor (eGHR1) and eGHR1 homologue (eGHR2) in Japanese eel (Anguilla japonica). In the present study, changes in the developmental expression of growth hormone (GH), eGHR1 and eGHR2 were investigated in the Japanese eel eggs and preleptocephali by RT-PCR and immunohistochemical methods in an attempt to examine the involvement of these proteins in larval growth. The GH transcripts and the production of GH protein were not detected in the newly hatched larvae and preleptocephali at day 3 post-hatch, however, these were detected at day 6 post-hatch, and also detected at higher levels at day 10 post-hatch. In contrast, prolactin and somatolactin transcripts could not be detected in all preleptocephalus specimens (newly hatched larvae and preleptocephali at day 3, 6 and 10 post-hatch). eGHR1 and eGHR2 transcripts were detected in all preleptocephalus specimens. Therefore, it is plausible that the actions of GH during the preleptocephalus stage are mediated through the eGHRs. The present data suggest that GHR-mediated actions of GH begin at the same time as the initiation of GH production, and that GH plays important roles in larval growth and survival to the leptocephalus stage. eGHR1 mRNA, which is thought to be of maternal origin, was also detected in ovulated eggs. However, the role of eGHR1 mRNA in eggs is not clear.

Anguilla↗
PubMed2006

Quantum sieving effect of modified activated carbon fibers on H2 and D2 adsorption at 20 K.

Quantum sieving of activated carbon fibers (ACFs) and their fluorides was observed for H(2) and D(2) adsorption at 20 K. Fluorination reduced the slit-shaped pore width of ACFs by 0.2 nm. The activated carbon fibers can act as highly efficient quantum sieves for H(2) and D(2), because the effective size of an H(2) molecule is larger than that of a D(2) molecule due to the uncertainty principle and the molecular size difference between H(2) and D(2) is significant in the micropore space. The D(2)/H(2) selectivity of ACFs evaluated by ideal adsorption solution theory was larger than that of the fluorinated ACFs.

Journal Article↗
PubMed2006

Close-packed structures and phase diagram of soft spheres in cylindrical pores.

It is shown for a model system consisting of spherical particles confined in cylindrical pores that the first ten close-packed phases are in one-to-one correspondence with the first ten ways of folding a triangular lattice, each being characterized by a roll-up vector like the single-walled carbon nanotube. Phase diagrams in pressure-diameter and temperature-diameter planes are obtained by inherent-structure calculation and molecular dynamics simulation. The phase boundaries dividing two adjacent phases are infinitely sharp in the low-temperature limit but are blurred as temperature is increased. Existence of such phase boundaries explains rich, diameter-sensitive phase behavior unique for cylindrically confined systems.

Journal Article↗
PubMed2006

Solution-processed silicon films and transistors.

The use of solution processes-as opposed to conventional vacuum processes and vapour-phase deposition-for the fabrication of electronic devices has received considerable attention for a wide range of applications, with a view to reducing processing costs. In particular, the ability to print semiconductor devices using liquid-phase materials could prove essential for some envisaged applications, such as large-area flexible displays. Recent research in this area has largely been focused on organic semiconductors, some of which have mobilities comparable to that of amorphous silicon (a-Si); but issues of reliability remain. Solution processing of metal chalcogenide semiconductors to fabricate stable and high-performance transistors has also been reported. This class of materials is being explored as a possible substitute for silicon, given the complex and expensive manufacturing processes required to fabricate devices from the latter. However, if high-quality silicon films could be prepared by a solution process, this situation might change drastically. Here we demonstrate the solution processing of silicon thin-film transistors (TFTs) using a silane-based liquid precursor. Using this precursor, we have prepared polycrystalline silicon (poly-Si) films by both spin-coating and ink-jet printing, from which we fabricate TFTs with mobilities of 108 cm2 V(-1) s(-1) and 6.5 cm2 V(-1) s(-1), respectively. Although the processing conditions have yet to be optimized, these mobilities are already greater than those that have been achieved in solution-processed organic TFTs, and they exceed those of a-Si TFTs (< or = 1 cm2 V(-1) s(-1)).

Journal Article↗
PubMed2006

Y-40138, a multiple cytokine production modulator, protects against D-galactosamine and lipopolysaccharide-induced hepatitis.

Acute and fulminant liver failure induced by viral hepatitis, alcohol or other hepatotoxic drugs are associated with tumor necrosis factor (TNF) production. D-Galactosamine (D-GalN) and lipopolysaccharide (LPS)-induced liver injury is an experimental model of fulminant hepatic failure. In this model, TNF-alpha plays a central role in the pathogenesis of D-GalN/LPS-induced liver injury in mice. Y-40138, N-[1-(4-[4-(pyrimidin-2-yl)piperazin-1-yl]methyl phenyl)cyclopropyl] acetamide.HCl inhibits TNF-alpha and augments interleukin (IL)-10 production in LPS-injected mice in plasma. In the present study, we examined the effect of Y-40138 on D-GalN/LPS-induced hepatitis. Y-40138 (10mg/kg, i.v.) significantly suppressed TNF-alpha and monocyte chemoattractant protein-1 (MCP-1) production and augmented IL-10 production in plasma. In addition, Y-40138 significantly inhibited TNF-alpha production induced by direct interaction between human T lymphocytes and macrophages. Y-40138 suppressed plasma alanine transaminase (ALT) elevation and improved survival rate in D-GalN/LPS-injected mice, and it is suggested that the protective effect of Y-40138 on hepatitis may be mediated by inhibition of TNF-alpha and MCP-1, and/or augmentation of IL-10. This compound is expected to be a new candidate for treatment of cytokine and/or chemokine-related liver diseases such as alcoholic hepatitis.

Acetamides↗
PubMed2006

Epidermoid tumor arising in the anterior interhemispheric fissure.

There have only been 18 cases reported in the literature of an epidermoid tumor arising in the interhemispheric fissure. We report a 45-year-old woman with an epidermoid tumor arising in the interhemispheric fissure. She presented with a focal convulsive seizure. Radiological imaging identified a tumor in the interhemispheric fissure, which was subtotally removed due to adherence to both anterior cerebral arteries and the cerebral cortex. Epidermoid tumor was confirmed by histopathology. Epidermoid tumors rarely arise in the interhemispheric fissure, but are often adherent to surrounding structures and thus, as in the presented case, complete resection may be unwise.

Brain Neoplasms↗
PubMed2006

Effects of gas adsorption on the electrical conductivity of single-wall carbon nanohorns.

We present significant electrical conductivity responses of the pelletized as-prepared and oxidized (ox-) single-wall carbon nanohorns (SWNHs) on adsorption of CO(2) and O(2). The morphological and pore structures of both pelletized SWNHs were examined by transmission electron microscopy (TEM) and nitrogen adsorption isotherm, leading to explicit evidences of the formation of nanoscale windows on the wall by oxidation. The SWNH and ox-SWNH induced a semiconducting behavior, strongly responded to CO(2) and O(2) adsorptions, and each exhibited n-type- and p-type-like conductivities. The electrical conductivity increase and decrease for CO(2) and O(2) adsorption, respectively, were observed for SWNH, whereas ox-SWNH showed a marked electrical conductivity drop on CO(2) adsorption and almost no change on O(2) adsorption. The dramatically different electrical conductivity response of ox-SWNH is presumed to be ascribed to the annihilation of pentagons in the single graphene wall by oxidation.

Adsorption↗
PubMed2006

Novel expansion/shrinkage modulation of 2D layered MOF triggered by clathrate formation with CO(2) molecules.

Crystal-to-crystal transformation from a 3D interpenetrated-type MOF {[Cu(BF(4))(2)(bpy)(H(2)O)(2)] (bpy)} (1) to a 2D square-grid-type [Cu(BF(4))(2)(bpy)(2)] (2) (bpy = 4,4'-bipyridine) was observed. It was derived from dehydration and confirmed by in situ FT-IR, TG, and elemental analysis. Moreover, we elucidate the novel expansion/shrinkage dynamic modulation of 2 triggered by clathrate formation with gas molecules.

Adsorption↗
PubMed2006

Effects of acute simulated microgravity on nocturnal sleep, daytime vigilance, and psychomotor performance: comparison of horizontal and 6 degrees head-down bed rest.

This study examined the effect of acute simulated microgravity on nocturnal sleep, daytime vigilance, and psychomotor performance. Each of 7 volunteers were maintained for 3 days of head-down and horizontal bed rest in a counter-balanced design. Assessment measures were polysomnographic recordings on the first night and performance on psychophysiological tasks on the second day involving subjective and objective vigilance, P300, simple reaction time tasks, and dual performance tasks. No clear difference in sleep structure was observed between the head-down and horizontal conditions, except for a slight decrease in Stage 4 for head-down. Both subjective and objective daytime vigilance, P300, and the simple RT task showed no statistical difference, although tracking performance on the dual task showed deterioration at 10:00 for the head-down condition. These results suggest that nocturnal sleep, daytime vigilance, and psychophysiological functions were not disturbed in head-down sleep conditions, although there was a mild deterioration of higher attentional function in the morning.

Adult↗
PubMed2005

Lipopolysaccharide stimulates the production of prostaglandin E2 and the receptor Ep4 in osteoblasts.

Previous studies have indicated that one of the causes of alveolar bone destruction with periodontitis is lipopolysaccharide (LPS) from the cell wall of gram-negative bacteria in plaque, and that prostaglandin E(2) (PGE(2)) is one of the bone resorption factors that stimulate osteoclast formation through an intercellular interaction between osteoblasts and osteoclast precursors. The present study was undertaken to determine the effect of LPS on cell growth, alkaline phosphatase (ALPase) activity, the production of PGE(2), and the expression of receptors by PGE(2), cyclooxygenase (COX)-1, and COX-2, using human osteosarcoma cell line Saos-2 as osteoblasts. The cells were cultured with 0, 1, or 10 microg mL(-1) of LPS for up to 14 days. The production of PGE(2) and the gene expression of COX-1, COX-2, and PGE(2) receptors, including Ep1, Ep2, Ep3, and Ep4, were determined using enzyme-linked immunosorbent assay (ELISA) and real-time reverse transcription-polymerase chain reaction (real-time RT-PCR), respectively. With the addition of LPS, cell growth and ALPase activity decreased by day 5 of the culture, while PGE(2) production increased in a dose-dependent manner throughout the entire 14-day culture period. LPS-reduced ALP activity and LPS-induced PGE(2) production returned to the control level by the addition simultaneously with indomethacin. The expression of COX-1, Ep1, Ep2, and Ep3 receptors decreased on day 14 of the culture, whereas the expression of COX-2 and Ep4 receptors increased significantly with the addition of LPS. These results suggest that LPS promotes PGE(2) production by increasing the expression of COX-2, and that LPS promotes the production of Ep4 receptors in osteoblasts. These results also indicate that LPS-induced PGE(2) may combine with osteoblast Ep4 receptors in autocrine or paracrine modes, and may promote the formation of osteoclasts.

Alkaline Phosphatase↗
PubMed2005

Nicotine and lipopolysaccharide stimulate the formation of osteoclast-like cells by increasing macrophage colony-stimulating factor and prostaglandin E2 production by osteoblasts.

Several studies have indicated that one of the causes of alveolar bone destruction with periodontitis is lipopolysaccharide (LPS) from the cell wall of Gram-negative bacteria in plaque and that tobacco smoking may be an important risk factor for the development and severity of periodontitis. The present study was undertaken to determine the effect of nicotine and LPS on the expression of macrophage colony-stimulating factor (M-CSF), osteoprotegerin (OPG), and prostaglandin E2 (PGE2) in osteoblasts, and the indirect effect of nicotine and LPS on the formation of osteoclast-like cells. Saos-2 cells were cultured with 10(-3) M nicotine, or 1 or 10 microg/ml LPS and 10(-3) M nicotine, for up to 14 days. The gene and protein expression of M-CSF and OPG were determined using real-time PCR and ELISA, respectively. PGE2 expression was determined using ELISA. The formation of osteoclast-like cells was estimated using tartrate-resistant acid phosphatase (TRAP) staining of osteoclast precursors in culture with conditioned medium from nicotine and LPS-treated Saos-2 cells and the soluble receptor activator of NF-kappaB ligand (RANKL). M-CSF and PGE2 expression increased markedly in cells cultured with nicotine and LPS compared with those cultured with nicotine alone. OPG expression increased in the initial stages of culture with nicotine and LPS but decreased in the later stages of culture. The conditioned medium containing M-CSF and PGE2 produced by nicotine and LPS-treated Saos-2 cells with soluble RANKL increased the TRAP staining of osteoclast precursors compared with that produced by nicotine treatment alone. These results suggest that nicotine and LPS stimulate the formation of osteoclast-like cells via an increase in M-CSF and PGE2 production and that the stimulation is greater than with nicotine treatment alone.

Alkaline Phosphatase↗
PubMed2005

Nicotine affects mineralized nodule formation by the human osteosarcoma cell line Saos-2.

Several in vitro and in vivo studies have indicated that tobacco smoking may be an important risk factor for the development and severity of inflammatory periodontal disease. In the present study, we examined the effect of nicotine on cell proliferation, alkaline phosphatase (ALPase) activity, mineralized nodule formation, and the expression of extracellular matrix proteins in the human osteosarcoma cell line Saos-2. The cells were cultured with Dulbecco's modified Eagle medium containing 10% fetal bovine serum with 0, 10(-4) M, and 10(-3) M nicotine for up to 14 days. Mineralized nodule formation was examined by alizarin red staining, and the calcium content in mineralized nodules was determined using a calcium E-test kit. The expression of extracellular matrix proteins was estimated by determining the levels of their mRNAs using the real-time polymerase chain reaction. Mineralized nodule formation and calcium content in mineralized nodules were remarkably suppressed by nicotine on days 10 and 14 of culture, respectively. ALPase activity as well as type I collagen and osteopontin expression also decreased in the presence of nicotine after 5, 10, and 14 days of culture, respectively. By contrast, the amount of bone sialoprotein increased during 14 days of culture with nicotine. These results suggest that nicotine suppresses osteogenesis through a decrease in ALPase and type I collagen production by osteoblasts.

Alkaline Phosphatase↗
PubMed2005

Storage of hydrogen at 303 K in graphite slitlike pores from grand canonical Monte Carlo simulation.

Grand canonical Monte Carlo (GCMC) simulations were used for the modeling of the hydrogen adsorption in idealized graphite slitlike pores. In all simulations, quantum effects were included through the Feynman and Hibbs second-order effective potential. The simulated surface excess isotherms of hydrogen were used for the determination of the total hydrogen storage, density of hydrogen in graphite slitlike pores, distribution of pore sizes and volumes, enthalpy of adsorption per mole, total surface area, total pore volume, and average pore size of pitch-based activated carbon fibers. Combining experimental results with simulations reveals that the density of hydrogen in graphite slitlike pores at 303 K does not exceed 0.014 g/cm(3), that is, 21% of the liquid-hydrogen density at the triple point. The optimal pore size for the storage of hydrogen at 303 K in the considered pore geometry depends on the pressure of storage. For lower storage pressures, p < 30MPa, the optimal pore width is equal to a 2.2 collision diameter of hydrogen (i.e., 0.65 nm), whereas, for p congruent with 50MPa, the pore width is equal to an approximately 7.2 collision diameter of hydrogen (i.e., 2.13 nm). For the wider pores, that is, the pore width exceeds a 7.2 collision diameter of hydrogen, the surface excess of hydrogen adsorption is constant. The importance of quantum effects is recognized in narrow graphite slitlike pores in the whole range of the hydrogen pressure as well as in wider ones at high pressures of bulk hydrogen. The enthalpies of adsorption per mole for the considered carbonaceous materials are practically constant with hydrogen loading and vary within the narrow range q(st) congruent with 7.28-7.85 kJ/mol. Our systematic study of hydrogen adsorption at 303 K in graphite slitlike pores gives deep insight into the timely problem of hydrogen storage as the most promising source of clean energy. The calculated maximum storage of hydrogen is equal to approximately 1.4 wt %, which is far from the United States Department of Energy (DOE) target (i.e., 6.5 wt %), thus concluding that the total storage amount of hydrogen obtained at 303 K in graphite slitlike pores of carbon fibers is not sufficient yet.

Journal Article↗
PubMed2005

Formation of ice nanotube with hydrophobic guests inside carbon nanotube.

A composite ice nanotube inside a carbon nanotube has been explored by molecular-dynamics and grand canonical Monte Carlo simulations. It is made from an octagonal ice nanotube whose hollow space contains hydrophobic guest molecules such as neon, argon, and methane. It is shown that the attractive interaction of the guest molecules stabilizes the ice nanotube. The guest occupancy of the hollow space is calculated by the same method as applied to clathrate hydrates.

Journal Article↗