Publications by authors named "Yumiko Katayama"

: Vericiguat has been shown to reduce cardiovascular mortality and hospitalisation for heart failure in patients with reduced ejection fraction. While Vericiguat is considered one of the standard treatments for heart failure, it is unclear under which conditions Vericiguat would be most effective. With a focus on the prognosis and improved EF of heart failure, we aimed to investigate in which cases Vericiguat is suitable for use in addition to standard cardioprotective drugs.

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The dynamics of the first-order phase transitions involving a large displacement of atoms, for example, a liquid-solid transition, is generally dominated by the nucleation of the ordered phase and the growth of the nuclei, where the interfacial energy between the two phases plays an important role. On the other hand, electronic phase transitions seldom exhibit such a nucleation-growth behavior, probably because two-phase coexistence is not dominated by only the interfacial energy in such phase transitions. In the present paper, we report that the dynamics of a phase transition associated with an ordering of d orbitals in a vanadate exhibits a clear nucleation-growth behavior and that the interfacial energy between the orbital-ordered and -disordered phases dominated by the orbital-spin coupling can be experimentally obtained.

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Superconducting FeSeTe thin films on SrTiO, LaAlO and CaF substrates were electrochemically etched in an ionic liquid, DEME-TFSI, electrolyte with a gate bias of 5 V. Superconductivity at 38 K was observed on all substrates after the etching of films with a thickness greater than 30 nm, despite the different T values of 8 K, 12 K and 19 K observed before etching on SrTiO, LaAlO and CaF substrates, respectively. T returned to its original value with the removal of the gate bias.

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Various positron emission tomography (PET) probes have been developed to assess in vivo activities in humans of drug transporters, which aid in the prediction of pharmacokinetic properties of drugs and the impact of drug-drug interactions. We developed a new PET probe, sodium (3, 5)-3, 5-dihydroxy-7-((1 2, 6, 8)-6-hydroxy-2-methyl-8- ((1-[C]-()-2-methyl-but-2-enoyl) oxy) -1, 2, 6, 7, 8, 8-hexahydronaphthalen-1-yl) heptanoate ([C]DPV), and demonstrated its usefulness for the quantitative investigation of Oatps (gene symbol ) and Mrp2 (gene symbol ) in rats. To further analyze the species differences and verify the pharmacokinetic parameters in humans, serial PET scanning of the abdominal region with [C]DPV was performed in six healthy volunteers with and without an OATP1Bs and MRP2 inhibitor, rifampicin (600 mg, oral), in a crossover fashion.

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We have developed a novel persistent phosphor of LaAlO perovskite doped with Er, Cr, and Sm (LAO:Er-Cr-Sm), which exhibits long persistent luminescence (PersL) at 1553 nm due to the Er:I→I transition as well as at 734 nm due to the Cr:E(G) →A(F) transition. The intense near-infrared (NIR) PersL bands from Cr and Er match well with the first (NIR-I, 650-950 nm) and third (NIR-III, 1500-1800 nm) biological windows as well as response curves of commercial Si and InGaAs detectors. The photon emission rates of Cr (6.

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Purpose: To select appropriate antiemetics relieving teriparatide-induced nausea and vomiting during osteoporosis treatment using PET molecular imaging and pharmacokinetic analysis.

Methods: Rats were pretreated with subcutaneous teriparatide, followed by oral administration of antiemetics with different pharmacological effects. The pharmacokinetics of antiemetics were assessed by oral administration of 2-deoxy-2-[(18)F]fluoro-D-glucose ([(18)F]FDG) under free moving conditions in vivo.

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Homeostasis is known to be involved in maintaining the optimal internal environment, helping to achieve the best performance of biological functions. At the same time, a deviation from optimal conditions often attenuates the performance of biological functions, and such restricted performance could be considered as individual fatigue, including physical and mental fatigue. The present study seeks to develop an animal model of chronic or subacute fatigue in which the recovery time is extended through the gradual disruption of homeostasis.

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We performed positron emission tomography (PET) using 2-deoxy-2-[(18)F]fluoro-D-glucose ([(18)F]FDG) to evaluate the pharmacokinetics of nasal drug absorption in the rat. The dosing solution of [(18)F]FDG was varied in volume (ranging from 5 to 25 μl) and viscosity (using 0% to 3% concentrations of hydroxypropylcellulose). We modeled the pharmacokinetic parameters regarding the nasal cavity and pharynx using mass balance equations, and evaluated the values that were obtained by fitting concentration-time profiles using WinNonlin® software.

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Purpose: To evaluate the function of multidrug and toxin extrusion proteins (MATEs) using (11)C-labeled metformin ([(11)C]metformin) by positron emission tomography (PET).

Methods: PET was performed by intravenous bolus injection of [(11)C]metformin. Pyrimethamine at 0.

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In order to develop a new positron emission tomography (PET) probe to study hepatobiliary transport mediated by the multi-drug and toxin extrusion transporter 1 (MATE1), (11)C-labelled metformin was synthesized and then evaluated as a PET probe. [(11)C]Metformin ([(11)C]4) was synthesized in three steps, from [(11)C]methyl iodide. Evaluation by small animal PET of [(11)C]4 showed that there was increased concentrations of [(11)C]4 in the livers of mice pre-treated with pyrimethamine, a potential inhibitor of MATEs, inhibiting the hepatobiliary excretion of metformin.

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We developed a pravastatin derivative, sodium (3R,5R)-3,5-dihydroxy-7-((1S,2S,6S,8S)-6-hydroxy-2-methyl-8-((1-[(11)C]-(E)-2-methyl-but-2-enoyl)oxy)-1,2,6,7,8,8a-hexahydronaphthalen-1-yl)heptanoate ([(11)C]DPV), as a positron emission tomography (PET) probe for noninvasive measurement of hepatobiliary transport, and conducted pharmacokinetic analysis in rats as a feasibility study for future clinical study. Transport activities of DPV in freshly isolated rat hepatocytes and rodent multidrug resistance-associated protein 2 (rMrp2; human, MRP2)-expressing membrane vesicles were similar to those of pravastatin. Rifampicin diminished the uptake of DPV and pravastatin by the hepatocytes, with similar inhibition potency.

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To develop potent drugs for oral use, information on their pharmacokinetic (PK) properties after oral administration is of great importance. We have recently reported the utility of positron emission tomography (PET) for the analysis of gastrointestinal (GI) absorption of radiolabeled compounds. In this study, PET image analysis was performed in rats using a novel PET probe, [(18)F]deoxyfluoropoly(ethylene glycol)s, with an average molecular weight of 2 kDa ([(18)F]FPEG), as a nonabsorbable marker to elaborate the GI physiology in more detail, such as segmental transition of the administered water, and fluid volume and distribution in the intestine.

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Unlabelled: A quantitative PET imaging method was used to assess the in vivo kinetics of hepatobiliary and renal excretion of the breast cancer resistance protein (Bcrp) substrate (11)C-SC-62807 in mice.

Methods: Serial abdominal PET scans were collected in wild-type and Bcrp knockout (Bcrp(-/-)) mice after intravenous injection of (11)C-SC-62807. Venous blood samples and PET images were obtained at frequent intervals up to 30 min after radiotracer administration.

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Purpose: To dynamically analyze the processes of oral absorption and hepatobiliary distribution of telmisartan using positron emission tomography (PET).

Methods: (11)C-labeled telmisartan ([(11)C]TEL) was orally administered to rats with or without non-radiolabeled telmisartan (0.5, and 10 mg/kg).

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Background: We evaluated the utility of L-3,4-dihydroxy-6-[18F]fluoro-phenylalanine ([18F]FDOPA) positron emission tomography (PET) as a method for assessing the severity of dopaminergic dysfunction in unilaterally 6-hydroxydopamine (6-OHDA)-lesioned rats by comparing it with quantitative biochemical, immunohistochemical, and behavioral measurements.

Methods: Different doses of 6-OHDA (0, 7, 14, and 28 μg) were unilaterally injected into the right striatum of male Sprague-Dawley rats. Dopaminergic functional activity in the striatum was assessed by [18F]FDOPA-PET, measurement of striatal dopamine (DA) and DA metabolite levels, tyrosine hydroxylase (TH) immunostaining, and methamphetamine-induced rotational testing.

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The synthesis and in vivo evaluation of (11)C -labeled uric acid ([(11)C]1), a potential imaging agent for the diagnosis of urate-related life-style diseases, was performed using positron emission tomography (PET) image analysis. First, the synthesis of [(11)C]1 was achieved by reacting 5,6-diaminouracil (2) with (11)C-labeled phosgene ([(11)C]COCl(2)). The radiochemical yield of [(11)C]1 was 37±7% (decay-corrected based on [(11)C]COCl(2)) with specific radioactivities of 96-152GBq/μmol at the end of synthesis (n=6).

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Telmisartan, a selective angiotensin II receptor antagonist, is primarily excreted via hepatobiliary transport. The predominant contribution of organic anion transporting polypeptide (OATP) 1B3 in its hepatic uptake of telmisartan has been demonstrated by in vitro transport studies. In the present study, a quantitative positron emission tomography (PET) methodology was developed for in vivo kinetic assessment of hepatobiliary transport of telmisartan.

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Synthesis of [(11)C]celecoxib, a selective COX-2 inhibitor, and [(11)C]SC-62807, a major metabolite of celecoxib, were achieved and the potential of these PET probes for assessing the function of drug transporter in biliary excretion was evaluated. The synthesis of [(11)C]celecoxib was achieved in one-pot by reacting [(11)C]methyl iodide with an excess of the corresponding pinacol borate precursor using Pd(2)(dba)(3), P(o-tolyl)(3), and K(2)CO(3) (1:4:9) in DMF. The radiochemical yield of [(11)C]celecoxib was 63±23% (decay-corrected, based on [(11)C]CH(3)I) (n=7) with a specific radioactivity of 83±23GBq/μmol (n=7).

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The bispectral index (BIS) was evaluated as an indicator of central nervous system (CNS) depression in horses anesthetized with propofol. Five non-premedicated horses were anesthetized with 7 mg/kg, IV propofol and the minimum infusion rate (MIR) of propofol required to maintain anesthesia was determined during intermittent positive pressure ventilation in each horse. The BIS was determined 20 min later and after stabilization at 2.

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Ethyl alpha-D-glucoside (alpha-EG) is a peculiar component in sake, a traditional Japanese alcoholic beverage. In this study, morphological changes in kidney and effects on urine excretion by alpha-EG ingestion were investigated. After the rats were fed with pellet diets containing 100% or 20% alpha-EG dietary level, alpha-EG was detected in urine and urine volume showed significant increase (p<0.

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