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Biomedical subjects

M Ochiai

Publications and source records attributed to M Ochiai.

At least 217 records · Page 12Linked to original sources
PubMed1983

Synthesis and structure-activity relationships of carbapenems related to C-19393 H2.

By applying the synthetic process reported in our previous paper, we synthesized new carbapenems having various (substituted) thio and alkoxy groups at the C(3) position and 1-hydroxy-1-methylethyl and analogous groups at the C(6) position with cis- and trans-stereochemistry; the in vitro antibacterial and beta-lactamase inhibitory activities of these new carbapenems were examined. Compared to C-19393 H2, some of these compounds (e.g., 11A-a-3 approximately 5) showed improved in vitro antibacterial activity especially against Pseudomonas aeruginosa; they showed a strong beta-lactamase inhibitory activity as well. Two noteworthy effects of substituent variation at the C(6) position on the activities were observed: 1) the trans-configuration caused a definite loss; and 2) introduction of 1-hydroxycyclobutyl and 1-hydroxy-1-methylpropyl groups in place of the 1-hydroxy-1-methylethyl group caused a diminution. The carbapenem (13A-a-2) with an alkoxy group at the C(3) position had a marked decrease in activity compared to the corresponding thio-substituted carbapenem (11A-a-12).

Indicators and Reagents↗
PubMed1982

[Two-dimensional echocardiographic evaluation of the right ventricular wall in hypertension and hypertrophic cardiomyopathy].

The thickness and motion of the right ventricular wall (RVW) were studied with two-dimensional echocardiography from a subxiphoid approach in 20 normal subjects (N Group), 86 patients with hypertension (HT Group) and 20 patients with hypertrophic cardiomyopathy (HCM Group). Comparison was made between the patients with and without echocardiographic RVW hypertrophy in each patient group in regard to the thickness of the interventricular septum (IVS) and the left ventricular posterior wall (LVPW) as well as the motion of the RVW and cardiac catheterization data. 1. RVW hypertrophy was visualized in 39.5% of the HT Group and in 40% of the HCM Group. There was no difference in the thickness of RVW between the two groups. 2. A localized hypertrophy and an abnormal motion of RVW were obtained in the HCM Group, but not in the HT Group. 3. RVW hypertrophy in the HT Group was seen in patients with marked IVS hypertrophy, while that in the HCM Group was not related to IVS hypertrophy. 4. Pulmonary arterial pressure remained normal in each group. Therefore, RVW hypertrophy did not appear to be the result of pressure overload. 5. Right atrial mean pressure and right ventricular end-diastolic pressure were elevated only in HCM patients with RVW hypertrophy. We conclude that there is a different mechanism in the mode of production of RVW hypertrophy between patients with hypertension and those with hypertrophic cardiomyopathy.

Cardiac Volume↗
PubMed1982

[Analysis of end-systolic pressure-volume relation by gated radionuclide angiocardiography].

Left ventricular end-systolic pressure-volume relation has been proved experimentally to be an useful index of left ventricular contractility relatively independent of preload or afterload. But less clinical application has been reported because of its invasive nature, and we evaluated this relationship non-invasively using gated radionuclide angiocardiography as volume determination and cuff sphyngomanometer in the arm as pressure measurement. Gated equilibrium blood pool scintigrams were obtained at rest and during intravenous infusion of angiotensin or nitrate. Ventricular volumes were derived from ventricular activity and peripheral blood volume and activity. The peak systolic pressure (PSP) by cuff method to end-systolic volume index (ESVI) relations showed good linearity (r greater than .930 in 84% of consecutive 50 cases) and were gentler in the groups with more impaired left ventricular function. Emax was related exponentially to ejection fraction (EF) and hyperbolically to end-diastolic volume index. The dead volume (VoI) was unfixed and fell into positive or negative value, and was not related to EF under control condition. PSP/ESVI in each loading condition was less variable with the alteration of blood pressure than EF. The linear relation was found between PSP/ESVI under control condition and Emax (PSP/ESVI = 0.651 . Emax + 0.958, r = 0.841, p less than .001). Thus in measuring ventricular volume, gated radionuclide angiocardiography is a non-invasive method less affected by the geometry of the left ventricle. Non-invasive determination of end-systolic pressure-volume relation using the volume by radionuclide and the blood pressure by cuff method is clinically useful in the assessment of left ventricular contractility.

Angiocardiography↗
PubMed1981

Synthesis and structure-activity relationships of 7 beta-[2-(2-aminothiazol-4-yl)acetamido]cephalosporin derivatives. IV. Synthesis of 2-(2-aminothiazol-4-yl)-2-methoxyiminoacetic acid derivatives and related compounds.

In an effort to improve the antibacterial activity of 7 beta-[2-(2-aminothiazol-4-yl)acetamido]-cephalosporins by introducing a methoxyimino group into the 7-acyl side chain, geometrically isomeric 2-(2-aminothiazol-4-yl)-2-methoxyiminoacetic acids and their derivatives were selectively synthesized. Structurally related acid derivatives were also synthesized. A facile and practical synthesis of an important starting material, 2-(2-chloroacetamidothiazol-4-yl)-(Z)-2-methoxyiminoacetic acid, for the preparation of SCE-1365 which is now under extensive clinical trial was achieved.

Anti-Bacterial Agents↗
PubMed1981

Synthesis and structure-activity relationships of 7 beta-[2-(2-aminothiazol-4-yl)acetamido]cephalosporin derivatives. V. Synthesis and antibacterial activity of 7 beta-[2-(2-aminothiazol-4-yl)-2-methoxyiminoacetamido]-cephalosporin derivates and related compounds.

In order to improve the antibacterial activity of 7 beta-[2-(2-aminothiazol-4-yl)acetamido]-cephalosporins new derivatives having a methoxyimino moiety in the 7-acyl side chain and related compounds were synthesized. Of these, 7 beta-[2-(2-aminothiazol-4-yl)-(Z)-2-methoxyiminoacetamido]-cephalosporins were found to possess excellent activity against a variety of Gram-positive and Gram-negative bacteria including beta-lactamase-producing strains. An extensive study of structure-activity relationships led to the selection of 7 beta-[2-(2-aminothiazol-4-yl)-(Z)-2-methoxyiminoacetamido]-3-[(1-methyl-1H-tetrazol-5-yl) thiomethyl]-ceph-3-em-4-carboxylic acid, SCE-1365, for further biological and clinical evaluation.

Bacteria↗
PubMed1981

[Analysis of left to right ventricular stroke count ratio by gated radionuclide angiocardiography: detection and quantitation of valvular regurgitation and shunts (author's transl)].

The stroke count ratio (SC ratio: SCL/SCR) for left to right ventricular enddiastolic-endsystolic count differences was obtained from LAO multi-gated cardiac blood pool scintigrams for quantitative assessment of valvular regurgitation and shunts. SC ratio, 1.48 +/- 0.24 (mean +/- S.D.) in 21 normal subjects, was decreased in 7 patients with atrial septal defects (ASD) and in one with isolated tricuspid regurgitation (TR), and increased in 15 patients with aortic regurgitation (AR) and in 6 with mitral regurgitation (MR). In post-surgical reassessment of 3 patients, the ratio was restored in normal range. Comparison between SC ratio and angiographic estimates of regurgitation revealed good agreement. Regurgitant fraction (RF) in AR or MR and shunt ratio (SR) in ASD were calculated by the formula: RF = 1-1.48/SC ratio, and SR = 1-SC ratio/1.48, respectively. These were derived by assuming that an excess of stroke counts was due to regurgitant or shunt flow and that the coefficient in counting ventricular radioactivity was 1.48. Agreement was found between RF or SR measured by this formula and by the invasive method. This method permits noninvasive quantitation in patients with valvular regurgitation and shunts without complicated computer procedures.

Aortic Valve Insufficiency↗
PubMed1980

An approach to broad-spectrum cephalosporins.

Based on our view that cephalosporins with potent activities share active hydrogen(s) on the alpha-carbon of the side chain acyl, we undertook to introduce beta-ketoacid moieties onto the cephalosporin structure. Thus, starting with deacetylcephalosporin C (DCPC), first made available in quantities by our own fermentation technique, 7-amino-3'-O-acetoacetyldeacetylcephalosporanic acid (7-AACA) was made accesible. Acylation of 7-AACA with various beta-ketoacids followed by substitution at the 3'-position led to 7 beta-[2-(2-aminothiazol-4-yl)acetamido]-3-[[1-(2-dimethylaminoethyl)-1H-tetrazol-5-yl]thiomethyl]ceph-3-em-4-carboxylic acid (SCE-963, cefotiam), a potent broad-spectrum cephalosporin. Further elaboration of the structure of cefotiam led to an extended broad-spectrum cephalosporin, SCE-1365. These two classes of cephalosporins, together with our previously reported antipseudomonal cephalosporin (SCE-129, cefsulodin), could control a wide range of pathogenic bacteria.

Bacteria↗
PubMed1980

Synthesis and structure-activity relationships of 7 beta-[2-(2-aminothiazol-4-yl)acetamido]-cephalosporin derivatives. I. Synthesis and antibacterial activity of 7 beta-[2-alkyl- and 2-hydroxy-2-(2-aminothiazol-4-yl)-acetamido]cephalosporins.

2-Alkyl- and 2-hydroxy derivatives of 7 beta-[2-aminothiazol-4-yl)acetamido]cephalosporins were synthesized to improve the antibacterial activity of the parent compounds especially against beta-lactamase-producing organisms. Some of these compounds showed an increase in activity against Serratia marcescens (Xb, XXIIIa) and Enterobacter cloacae (Xb, XIV). The 2,2-dimethyl derivative (XXVIIIb) showed a definite loss of activity.

Bacteria↗
PubMed1980

Synthesis and structure-activity relationships of 7 beta-[2-(2-aminothiazol-4-yl)acetamido]-cephalosporin derivatives. II. Synthesis and antibacterial activity of 7 beta-[2-(2-aminothiazol-4-yl)acetamido]-7 alpha-methoxycephalosporins.

7 beta-[2-(2-Aminothiazol-4-yl)acetamido]-7 alpha-methoxycephalosporins were synthesized both by acylation of the 7 beta-amino-7 alpha-methoxycephalosporin compound (VIII) and a new direct acyl-exchange reaction of 7 alpha-methoxy-7 beta-phosphoramido compound (VII). Some of these compounds (IXa, IXb) showed higher antibacterial activity than the 7 alpha-unsubstituted compound against beta-lactamase-producing strains of Serratia marcescens and Proteus vulgaris.

Bacteria↗
PubMed1980

Synthesis and structure-activity relationships of 7 beta-[2-(2-aminothiazol-4-yl)acetamido]-cephalosporin derivatives. III. Synthesis and antibacterial activity of 7 beta-[2-amino-2-(2-aminothiazol-4-yl)acetamido]cephalosporins.

New derivatives of 7 beta-[2-(2-aminothiazol-4-yl)acetamido]cephalosporins having amino group at the 2-position of the 7-acyl moiety were synthesized in the hope that they would show improved antibacterial activity. Some of these compounds (XXa, XXd, XVb) showed improved activity against Enterobacter cloacae. Replacement of the annular amino group by a methyl group caused loss of activity.

Bacteria↗
PubMed1980

Visualization of right atrial appendix by thallium-201 myocardial scintigraphy: concise communication.

The atrial myocardium has been barely visible with thallium-201 myocardial scintigraphy. This is probably related to the difference in size, distance from anterior chest wall, and small coronary blood flow of the atrium, compared with the ventricle. We have encountered eight cases of visualization of the right atrial appendix (RAA). All had disease involving the right side of the heart, such as mitral stenosis (four cases), congenital heart disease (two), cor pulmonale (one), and primary myocardial disease (one). The RAA was identified from multiple projections in all cases and sometimes confirmed by radionuclide angiocardiography. The RAA was seen at the right upper aspect of the ventricles and was distinguishable from them. Evidence derived from ECG, chest radiographs, and cardiac catheterization, indicated that the most important factor in the visualization might be the displacement of the RAA to a more anterior position.

Adult↗