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Biomedical subjects

Atsushi Hasegawa

Publications and source records attributed to Atsushi Hasegawa.

11 recordsLinked to original sources

Cis-bis[(3-aminopropyl)dimethylphosphine-kappa2N,P]palladium(II) dichloride methanol solvate.

In the title compound, cis-[Pd(C5H14NP)2]Cl2.CH4O, the coordination geometry around the PdII center is distorted square planar, with a cis-P2N2 configuration of the two chelating (3-aminopropyl)dimethylphosphine (pdmp) ligands. The six-membered pdmp chelate rings adopt chair conformations, and pairing of the chairs designates the complex cation as a (Cs)-chair2 conformer. The distances between the PdII center and the Cl- anions are greater than 4.5 A, indicating no obvious interaction.

Journal Article↗

Independent predictors of the severity of angiographic coronary atherosclerosis: the lack of association between impaired glucose tolerance and stenosis severity.

Independent predictors of the severity of coronary atherosclerosis are ill defined. We sought to determine the predictors and examine the association of impaired glucose tolerance with stenosis severity. Four hundred thirty-seven patients were studied who underwent coronary angiography for suspected coronary artery disease. Serum concentrations of total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDLc), lipoprotein(a) [Lp(a)] and apolipoproteins (Apo A-I and Apo B) were measured and low-density lipoprotein cholesterol (LDLc) concentration was calculated. Except the patients treated for diabetes mellitus (DM), patients were classified into three groups such as normal glucose tolerance (NGT), impaired glucose tolerance (IGT) and DM by glucose tolerance test. Coronary atherosclerosis index (CAI) representing the severity of coronary atherosclerosis was determined by summation of the stenosis score of all lesions on coronary angiograms. Results indicated that age, total amount of cigarettes smoked, Apo B/Apo A-I, and LDLc/HDLc correlated with CAI, whereas HDLc and Apo A-I concentrations inversely correlated with CAI. TC, TG, Lp(a), LDLc, Apo B concentrations and body mass index did not correlate with CAI. One- and two-hour plasma glucose concentrations and the area of plasma glucose concentration under the curve at the glucose tolerance test did not correlate with CAI, revealing that post-challenge glycemia is not associated with stenosis severity. CAI in IGT patients was significantly lower than that in DM patients but did not differ from that in NGT patients, indicating that IGT does not affect the stenosis severity. Multivariate analysis showed that age, male gender, Apo B/Apo A-I, DM, systemic hypertension, and total amount of cigarettes smoked were independent predictors of CAI.

Adolescent↗

Effects of continuous ingestion of green tea or grape seed extracts on the pharmacokinetics of midazolam.

Limited systematic data on herb-drug interaction are available, despite many opportunities to concomitant use of herb with prescribed drugs. We investigated the effects of 15 herbal extracts in dietary supplements on CYP2C9, CYP2D6 and CYP3A4 activities in human liver microsomes. Strong inhibition of these CYP activities was found by the addition of green tea extracts (GTE) or grape seed extracts (GSE) in vitro. To examine the effects of these extracts on CYP3A activities in vivo, the pharmacokinetics of midazolam (MDZ) was analyzed in rats. Although single treatments with these extracts had negligible effects, 1 week of treatment with them resulted in a significant increase in the ke of intravenously administered MDZ, indicating the induction of CYP3A in the liver. In contrast, 1 week of treatment with GTE, but not GSE, caused a significant increase in the C(max) and AUC(0-infinity) of orally administered MDZ without change in the t(1/2), suggesting a reduction in CYP3A activity in the small intestines. These studies indicate that subchronic ingestion of GTE or GSE may alter the pharmacokinetics of MDZ, and the effects of GTE on CYP3A activity appear opposite between liver and small intestine, which could not be predicted from in vitro experiments.

Adult↗

Experimental demonstration of quantum source coding.

We report an experimental demonstration of Schumacher's quantum noiseless coding theorem. Our experiment employs a sequence of single photons, each of which represents three qubits in terms of eight spatial and polarization modes. We initially prepare each photon in one of a set of eight nonorthogonal code word states corresponding to the value of a block of three binary letters. We use quantum coding to compress this quantum data into a two-qubit quantum channel and then uncompress the two-qubit channel to restore the original data with a fidelity approaching the theoretical limit.

Journal Article↗

Velocity measurement of clay intrusion through a sudden contraction step using a tagging pulse sequence.

Magnetic resonance imaging (MRI) with a spatial tagging sequence was used to measure the velocity distribution of clay that was forced past a sudden contraction. A spatial tagging sequence provided magnetic resonance images of clay that allowed measurement of the velocity distribution in the clay, which can provide profound insights on the deformation process of clay during the intrusion process. The experiments were conducted using a specially-designed vessel that could operate at up to 30 MPa. The vessel offers a rectangle test section with a sudden contraction step that had a ratio of contraction of 2:1. The vessel was installed into a commercial magnetic resonance imaging equipment and then the fluid motion of clay flowing into the narrow contracted channel was quantitatively investigated to examine behaviors of flowing clay as non-Newtonian fluid. MRI results are compared with those obtained by computational fluid dynamics (CFD) calculation. Velocity distributions obtained from each tag displacement did not well agree with those predicted by CFD results near the contraction step where the fluid accelerated rapidly. However, a post-processing on calculation results, in which virtual tag displacement is calculated, gave better agreement with experiment and enabled us to compare MRI results with CFD results.

Aluminum Silicates↗

[The interchange between hospital pharmacists and pharmacists: evaluation of practical classes "chozaigijutsu-konwakai" from the participants].

We have held practical classes called chozaigijutsu-konwakai(Konwakai) for pharmacists working in drugstores every month since December 1994. Konwakai is composed of lectures and practice. The practice is carried out for pharmacists to obtain a better understanding of prescriptions and compounding them in exercises. In this study, we analyzed the answers to questionnaires distributed at the end of each konwakai to all participants. It was found that the age of participants as well as the length of compounding experience varied markedly, indicating that pharmacists of various generations are interested in konwakai. Regarding the contents of lectures and practice, the answers indicated that the practice was particularly useful, suggesting the importance of exercise for learning techniques in compounding. Since there were many requests for consultations on routine work, frequent communications between pharmacists in the hospital and drugstores appears necessary. In conclusion, regular meetings including practical classes such as konwakai are very important for pharmacists in drugstores that receive prescriptions from hospitals. Further efforts to improve the konwakai should be maid in the future.

Community Pharmacy Services↗

Ultrasonic butt welding of aluminum, aluminum alloy and stainless steel plate specimens.

Welding characteristics of aluminum, aluminum alloy and stainless steel plate specimens of 6.0 mm thickness by a 15 kHz ultrasonic butt welding system were studied. There are no detailed welding condition data of these specimens although the joining of these materials are required due to anticorrosive and high strength characteristics for not only large specimens but small electronic parts especially. These specimens of 6.0 mm thickness were welded end to end using a 15 kHz ultrasonic butt welding equipment with a vibration source using eight bolt-clamped Langevin type PZT transducers and a 50 kW static induction thyristor power amplifier. The stainless steel plate specimens electrolytically polished were joined with welding strength almost equal to the material strength under rather large vibration amplitude of 25 microm (peak-to-zero value), static pressure 70 MPa and welding time of 1.0-3.0 s. The hardness of stainless steel specimen adjacent to a welding surface increased about 20% by ultrasonic vibration.

Journal Article↗

The relationship of the anterior drawer sign to the shape of the tibial plafond in chronic lateral instability of the ankle.

To determine what factors correlate with values for tested anterior drawer (AD) sign, we investigated stress radiographs in 71 patients with severe chronic lateral instability of the ankle as well as 320 normal controls. We found no correlation between AD and talar tilt (TT), but measurement of the anterior tip ratio (ATR) (ATR=tanA x 100) demonstrated a link of ATR with AD (r=0.74, p<0.001). The posterior tip ratio (PTR) (PTR=tanP x 100) was not correlated with AD (r=0.34, p=0.16). The ankle mortise angle (AMA) (the anterior opening of the lateral ankle mortise) was also not correlated with AD (r=0.27, p=0.23). Investigation of 320 normal ankles revealed a mean ATR of 9.1%+/-1.4%. The ATR in patients was 7.6%+/-1.7%, significantly lower than in the control patients. The values in female patients with chronic lateral instabilities were significantly less than the values in the females in the control group. But values for male patients were not different from the control group. Thus the anterior tip of the lateral tibial plafond, as it affects the ATR, may influence instability in anterior drawer function, especially in female patients with chronic lateral ligamentous instability of the ankle.

Adult↗

Effects of Kampo extracts on drug metabolism in rat liver microsomes: Rhei Rhizoma extract and Glycyrrhizae Radix extract inhibit drug oxidation.

In the present study, the effects on drug oxidations in rat liver microsomes in vitro using 126 Kampo extracts were investigated. Although the effects of inhibition on drug oxidations were dependent on the Kampo extracts and probe reactions studied, most of the Kampo extracts showed inhibitory effects on both N-demethylations of aminopyrine and erythromycin in rat liver microsomes. Among the Kampo extracts studied herein, Daio-kanzo-to exhibited the most remarkable inhibitory effect on both reactions. The Rhei Rhizoma extract inhibited not only aminopyrine and erythromycin N-demethylations, but also phenacetin O-deethylation, 7-ethoxycoumarin O-deethylation, ethanol oxidation and tolbutamide 4-hydroxylation in rat liver microsomes. The Glycyrrhizae Radix extract also showed a remarkable inhibitory effect on phenacetin O-deethylation as well as aminopyrine and erythromycin N-demethylations. In contrast, the Glycyrrhizae Radix extract virtually showed no effect on ethanol oxidation.

Animals↗

Identification of inhibitory component in cinnamon--O-methoxycinnamaldehyde inhibits CYP1A2 and CYP2E1-.

The Cinnamomi Cortex and Ephedra Herba were found to more strongly inhibit aminopyrine N-demethylation in rat liver microsomes compared to other constituents included in Sho-seiryu-to. The component inhibiting drug oxidations catalyzed by CYP1A2 and CYP2E1 was isolated from Cinnamomi Cortex, and was identified as o-methoxycinnamaldehyde (OMCA). When phenacetin and 4-nitrophenol were used as probe substrates for CYP1A2 and CYP2E1, respectively, the OMCA was shown to be a competitive inhibitor against CYP1A2 while it was a mixed type inhibitor against CYP2E1. The inhibitory effect of OMCA on 4-nitrophenol 2-hydroxylation (K(i)=6.3 microM) was somewhat potent compared to that observed on phenacetin O-deethylation (K(i)=13.7 microM) in rat liver microsomes.

Journal Article↗