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Biomedical subjects

Y Inamoto

Publications and source records attributed to Y Inamoto.

At least 19 recordsLinked to original sources
PubMed1995

Lipid composition and fatty acid analysis of Helicobacter pylori.

Lipids extracted from Helicobacter pylori were separated into lipid classes by thin-layer chromatography. Simple H. pylori lipids consisted of cholesterol esters, triglycerides, free fatty acids, cholesterol, diacylglycerols, and monoacylglycerols. Fatty acids were released from each lipid class by acid methanolysis, and analyzed by gas liquid chromatography and mass spectrometry. Unique methoxy fatty acids, including 11-methoxy heptadecanoic and 11-methoxy nonadecanoic acids, were the major components of the cholesterol esters and triglycerides. The predominance of methoxy fatty acids in the cholesterol esters of H. pylori may contribute to the acid-resistant characteristic of this bacillus.

Chromatography, Gas↗
PubMed1995

[Assessment of 201Tl myocardial SPECT reinjected at 24 hours after stress imaging].

To improve the quality of 24 hours delayed images (24 DL) of stress thallium-201 myocardial SPECT, reinjection was performed at 24 hours later (24 RI), and the results were compared with those of 24 DL. A total of 45 patients were studied, including 18 patients in 24 DL, 27 patients in 24 RI. All of them showed persistent defect or incomplete redistribution on the routine stress and 3 hours delayed SPECT scans. In 24 RI, 37 MBq of thallium-201 was reinjected at 24 hours later. Myocardial count of 24 DL was about 1/4 of stress image, while 24 RI was about 1/2. Quality of 24 RI image was nearly equal to 3 hours delayed image. Of regions without redistribution at 3 hours delayed image, 5 (36%) regions showed new redistribution at 24 RI. Of regions incomplete redistribution, 6 (25%) regions showed further redistribution. Compared with 24 DL, the frequency of redistribution tended to be higher in this protocol than that of the 24 DL (11%, 17% respectively). In conclusion, the reinjection at 24 hours delayed imaging was considered to be useful to evaluate viability of myocardium in patient with CAD.

Aged↗
PubMed1994

Reliability of data obtained by radionuclide angiocardiography in follow-up studies with special reference to intra- and interobserver variations.

The reproducibility of the data obtained by radionuclide angiocardiography was studied in terms of the intra- and intervariations of three technicians. Three parameters were chosen: the left ventricular ejection fraction (LVEF), the 1/3 filling fraction (1/3FF), and the ratio of the time from end systole to the point of peak filling rate against the entire diastolic period (TRPFR). First, each technician studied an independent consecutive series of 40 patients for the initial analysis. The original data of each patient, composed of 26 frames for one beat, were stored on an optical disc for the intra- and intervariation studies. In this study, analysis of the volume curve was performed by using both 3rd order and 4th order Fourier series. The region of interest (ROI) for the left ventricle, which was set for the initial analysis, was recorded by Polaroid photography to be used as a reference for the later analyses for the variation studies. The least variation was noted in the LVEF not only for the intravariation study but also for the intervariation study, no matter which order of the Fourier series was used. However, the 3rd order Fourier series seemed to give better curve fitting to avoid fluctuation of the diastolic parameters. The results indicate that we can expect more steady and reliable information from LVEF than from the diastolic parameters, even when various technicians perform the follow-up study of a particular patient.

Angiocardiography↗
PubMed1994

[Assessment of left ventricular count increase with ECG-gated 99mTc-MIBI SPECT using a single-head rotating gamma-camera].

ECG-gated 99mTc-MIBI SPECT was performed in 33 patients, including 17 normal subjects and 16 patients with old myocardial infarction. To compare the findings by echocardiography (UCG), regional wall motion was qualitatively assessed by cine-mode display and quantitatively measured as an increase in regional count from end-diastole to end-systole. The percent count increase and relative count increase was measured to display on the Bull's eye polar map. In the study of normal subjects, the count increase was greater in apical regions and smaller in septal regions. Regional wall motion by this method correlated well with UCG findings (agreement: 97%, complete agreement: 60%). A mild but significant correlation was observed between the count increase by this method and the percent wall thickening by UCG. We conclude that regional wall motion can be accurately evaluated with ECG-gated 99mTc-MIBI SPECT, which thus permits simultaneous assessment of regional wall motion and myocardial perfusion.

Aged↗
PubMed1994

[Phase I study of paclitaxel].

Paclitaxel, a novel antimicrotubule agent that enhances tubulin polymerization and microtubule stability, was administered as a 24-hour infusion in a phase I study. Twelve patients received 32 courses at 50, 100, 150, and 200 mg/m2. A premedication regimen of dexamethasone, diphenhydramine, and ranitidine was used to prevent the acute hypersensitivity reactions (HSRs). The dose-limiting factor was leukopenia (granulocytopenia) associated with Grade 4 infection. The maximum tolerated dose was 200 mg/m2. Other non-hematological effects included peripheral neuropathy, myalgia, alopecia, and elevations of transaminase and alkaline phosphatase. Severe HSRs were not observed. The paclitaxel plasma concentration declined with a half-life of 10.0 to 24.9 hours. Excretion into urine within 72 hours was in the range of 7.28 to 11.34% of paclitaxel dosage. Two patients with breast cancer at the 200 mg/m2 dose level had partial responses. The recommended dose of paclitaxel for phase II study, when administered as a 24-hour infusion, is considered to be 150 mg/m2 every 3 weeks.

Adolescent↗
PubMed1993

[Research and development of new oral cephems, cefixime and cefdinir].

This article reviews the structure-activity relationships, biological properties and synthesis of two new oral cephalosporin antibiotics, cefixime (CFIX) and cefdinir (CFDN). Our research into new oral cephalosporin antibiotics began in the late 1970's. The first goal of our research was to discover a new oral cephem possessing similar antibacterial activity and resistance to beta-lactamase as the 3rd generation injectable cephalosporins. We focused our attention on searching for a non-prodrug type cephem, that is, a new parent structure with high intrinsic absorption. We selected ceftizoxime (CZX) as a seed compound due to its relatively high excretion rate (8.5%) in the urine after oral administration to rats. We concentrated our research on the chemical modification of the oxime moiety in CZX based on our hypothesis for oral absorption, and discovered a lead compound with a carboxymethoxyimino group which displayed better urinary excretion (41.0%). Optimization studies led to a new oral cephem, CFIX. However, CFIX shows only low to moderate antibacterial activity against gram-positive bacteria such as S. aureus. Hence, the second goal of our research was to discover a new oral cephem with enhanced activity against gram-positive bacteria. From a consideration of structure-absorption relationships, we studied the activity and absorbability of cephems bearing other acidic functional groups at the oxime moiety of CFIX. As a result, we found a new oral cephem, CFDN with a hydroxyimino group at the 7-position. CFIX has excellent biological properties, displaying potent antibacterial activity against a wide range of gram-positive bacteria except S. aureus and gram-negative bacteria including opportunistic pathogens, high stability towards beta-lactamases and long acting efficacy. CFDN exhibits excellent and well balanced antibacterial activities against gram-positive and gram-negative bacteria. The pharmacokinetic of CFDN in healthy volunteers showed that serum levels were high enough to make CFDN as an effective antibacterial agent. The proposed mechanisms of intestinal absorption of CFIX and CFDN are briefly described. The efficient synthetic methods to CFIX and CFDN were achieved via a common intermediate, 7-amino-3-vinylcephalosporanic acid diphenylmethyl ester from 7-ACA.

Administration, Oral↗
PubMed1992

Ovarian and hepatic metastases of gastric carcinoma associated with high serum levels of human chorionic gonadotropin (hCG), alpha-fetoprotein (AFP), and carcinoembryonic antigen (CEA): a case report.

A 45-year-old woman who underwent gastrectomy for gastric carcinoma which had metastasized to the liver and ovaries, showed high serum levels of hCG, AFP and CEA. To locate the source, an immunohistochemical technique was utilized. HCG-producing cells were detected in poorly differentiated adenocarcinoma of a primary tumor and an ovarian metastatic site, and AFP-producing cells in poorly differentiated adenocarcinoma forming a medullary pattern of primary site and metastatic foci. CEA-producing cells were found diffused in primary tumor and metastatic foci. From the viewpoint of oncodevelopmental gene expression (Cancer Res 36:3423, 1976), it is interesting that the serum levels of these three tumor markers (hCG, AFP, CEA) were elevated simultaneously.

Biomarkers, Tumor↗
PubMed1992

[A new oral cephem, cefdinir: its structure-activity relationships and biological profile].

This article reviews structure-activity relationships and biological properties of a new oral cephem, cefidinir (CFDN). It also describes a hypothesis concerning the absorption mechanism from the intestine. Antibacterial activities and the oral absorption efficiencies were studied with regard to 3-vinyl cephalosporins with various 7-acyl side chains. From the study, 2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetyl group was selected and various 3-substituents were screened. As a result, it was found that the vinyl compound, CFDN, showed excellent antibacterial activity and good oral absorption in rats. In vitro and in vivo antibacterial activities, the affinity for PBPs and the stability to beta-lactamases revealed that CFDN had well balanced antimicrobial activities against Gram-positive and Gram-negative bacteria and good biological properties. The pharmacokinetics of CFDN in healthy volunteers showed that serum concentration and half life were good enough to make CFDN an effective therapeutic agent. The mechanism of intestinal absorption of CFDN and related oral cephems are discussed and a hypothesis for molecular recognition by the carrier protein in the intestine is proposed.

Animals↗
PubMed1991

Effect of hyperbaric oxygenation on macrophage function in mice.

Hyperbaric oxygenation (HBO) has an immunosuppressive effect. The possible mechanisms of this immunosuppressive effect were assessed by determining the production of interleukin-1 (IL-1), interleukin-6 (IL-6), and prostaglandin E2 (PGE2), as well as phagocytosis by splenic macrophages from HBO-treated mice. Although HBO treatment did not have any significant effect on IL-6 production and phagocytotic activity, a marked decrease in IL-1 production and a significant decrease in PGE2 production were observed. These results suggest that the reduction of IL-1 production may play an important role in the immunosuppressive effect of HBO.

Animals↗
PubMed1991

Studies on beta-lactam antibiotics. XIX. Structure-activity relationships of cephalosporins having a thiadiazolylthiomethyl group at the C-3 side chain.

The synthesis and antibacterial activity of 7 beta-[(Z)-2-(2-amino-4-thiazolyl)-2-(hydroxy or alkoxy)iminoacetamido]cephalosporins with various thiadiazolylthiomethyl moieties at the 3-position are discussed. Of the compounds (1a-1e, 7a-7d), 7 beta-[(Z)-2-(2-amino-4-thiazolyl)-2-hydroxyiminoacetamido]-3-[(1,2 ,4- thiadiazol-5-yl)thiomethyl]cephalosporin (1d: FK312) exhibited the highest activity against Gram-positive and Gram-negative bacteria, especially, against methicillin-resistant Staphylococcus aureus. Furthermore, the pharmacokinetic profiles of the compound 1d showed longer serum levels than that of ceftriaxone in rats.

Anti-Bacterial Agents↗
PubMed1990

Effect of interleukin 1 (IL-1) on the levels of cytochrome P-450 involving IL-1 receptor on the isolated hepatocytes of rat.

In the present study, the expression of IL-1 receptor (IL-1 R) on the primary cultured hepatocytes was determined and the effect of IL-1 on the intracellular amount of cytochrome P-450 was investigated. The kinetics of IL-1R on the hepatocytes was studied by [125I]-IL-1 alpha and revealed that 5,000 molecules of IL-1 bound to a hepatocyte with a Kd of 4.0 x 10(-9) M. Incubation of the hepatocytes with IL-1 for 18 hrs decreased the contents of cytochrome P-450 in a dose-dependent manner. These findings suggest that IL-1 potentially depresses the drug metabolism involving IL-1R which is expressed on hepatocytes.

Animals↗
PubMed1990

[Studies on FK482 (Cefdinir). IV. Synthesis and structure-activity relationships of 7 beta-[(Z)-2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]- 3-substituted cephalosporin derivatives].

The synthesis of 7 beta-[(Z)-2-(aminothiazol-4-yl)-2-hydroxyiminoacetamido] cephalosporins (Ia-i) modified at the C-3 position of a cephem nucleus and the effect of the C-3 substituents on the antibacterial activity and oral absorbability are discussed. The cephems (Ie, h and i) having a C-3 substituent such as 1-propenyl, ethylthio and vinylthio group as well as FK482 (cefdinir) exhibited excellent antibacterial activities against both gram-positive and gram-negative bacteria. However, those compounds showed poor absorption rate after oral administration in rats. It is concluded that the vinyl moiety at the 3-position is necessary to display fairly oral absorptivity in a series of 7 beta-[(Z)-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]c eph ems.

Animals↗
PubMed1990

[Studies on FK482. II. Synthesis and structure-activity relationships of 7 beta-[(Z)-2-(2-aminothiazol-4-yl)-2-substituted acetamido]-3-vinyl-3-cephem-4-carboxylic acid derivatives].

Various 7 beta-[2-(2-aminothiazol-4-yl)-2-substituted acetamido]-3-vinyl-3-cephem-4-carboxylic acid derivatives (Ia--e, IIa--g) were synthesized in order to find a new orally active cephalosporin improving the antibacterial activity of cefixime (CFIX) against Staphylococcus aureus. These derivatives include three types of alpha-substituted 2-(2-aminothiazol-4-yl)acetyl side chain; i) mono or non substituted acetyl moiety, ii) carboxyalkoxyimino acetyl moiety, iii) phosphonomethoxyimino and hydroxyimino acetyl moiety. Their structure-activity relationships and urinary recoveries in rats were studied. As a result, the compound with a hydroxyimino acetyl side chain (IIg, FK482) showed good oral absorption and excellent antibacterial activity against both gram-positive and gram-negative bacteria and was selected as a candidate for clinical trial.

Animals↗
PubMed1990

[Studies on FK482 (Cefdinir). III. Synthesis and structure-activity relationships of 7 beta-[(Z)-2-aryl-2-hydroxyiminoacetamido]-3-vinyl-3- cephem-4-carboxylic acid derivatives].

The synthesis, antibacterial activity and oral absorption of the 7 beta-[(Z)-2-aryl-2-hydroxyiminoacetamido]-3-vinylcephalosporins (Ia--e) are described. All of these compounds exhibited excellent activity against Staphylococcus aureus. Against Gram-negative bacteria FK482 exhibited more excellent activity than the other compounds (Ia--e). These compounds except Ie showed good oral absorption. The relationship between the oral absorption rates and the lipophilicity of these cephalosporins is discussed.

Animals↗