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Biomedical subjects

M Hamada

Publications and source records attributed to M Hamada.

At least 541 records · Page 30Linked to original sources
PubMed1985

N-Substituted derivatives of 23-amino-4',23-dideoxymycaminosyl tylonolide. Synthesis and antibacterial activity.

23-Amino-4',23-dideoxymycaminosyl tylonolide diethyl acetal (5) has been prepared from 4',23-dideoxy-23-iodomycaminosyl tylonolide diethyl acetal (3) by treatment with sodium azide followed by selective reduction of the resulting azide (4). 23-Acylamino-23-deoxy (6 approximately 8) and 23-deoxy-23-urethane-type compounds (12 approximately 15) were further prepared. Treatment of the 23-alkylamino-4',23-dideoxymycaminosyl tylonolides (9, 10) with chloroformates gave 23-N-alkyl-23-deoxy-23-urethane-type compounds (16 approximately 21, 29, 30). 23-N-Alkyl-23-deoxy-23-(2-hydroxyethalamino and 2-methoxyethylamino)-4',23-dideoxymycaminosyl tylonolides (22 approximately 25, 27, 28) were prepared from 3 and the corresponding amines. Antibacterial activities and toxicities (for 23 and 27) of these compounds are described. toxicities (for 23 and 27) of these compounds are described.

Bacteria↗
PubMed1985

[Computer system in radiotherapy].

Computer systematized radiotherapy is useful for; The use of diagnostic images for treatment planning; The accuracy of dose distribution; The automatic control of therapy machine; The statistical analysis of patients' documentation. Computer use for radiotherapy has been worked since 1969 in Japan. Radiotherapy documentation should be carried out to be able to judge the effect of the treatment given. A large number of patients are required to obtain a good judgement. Standardization of radiotherapy patient registration and data analysis of the treatment results co-related with radiation injury are described.

Computers↗
PubMed1984

Cryosurgery and OK 432 in the treatment of malignant melanoma.

We used concomitant therapy that consisted of cryosurgery and injection of OK 432 (a hemolytic streptococcal preparation) in the treatment of a giant malignant melanoma that primarily arose from the hard palate to the alveolar process in a 69-year-old man. The tumor consequently disappeared completely. One and a half years later, there are no signs of relapse.

Aged↗
PubMed1984

Ca2+,Mg2+-ATPase of microsomal membranes from bovine aortic smooth muscle. Identification and characterization of an acid-stable phosphorylated intermediate of the Ca2+,Mg2+-ATPase.

An acid-stable phosphoprotein was formed in a microsomal membrane fraction isolated from bovine aortic smooth muscle in the presence of Mg2+ + ATP and Ca2+. The microsomes also showed Ca2+ uptake activity. The Ca2+ dependence of phosphoprotein formation and of Ca2+ uptake occurred over the same range of Ca2+ concentration (1-10 microM), and resembled similar findings from rabbit skeletal microsomes. The molecular weight of the phosphorylated protein, estimated by SDS-gel electrophoresis, was approximately 105,000. The phosphoprotein was labile at alkaline pH, and its decomposition was accelerated by hydroxylamine. Half-maximum incorporation of 32P in the presence of 10 microM Ca2+ occurred at 60 nM ATP. The calcium-dependent phosphoprotein formation was not affected by 5 mM NaN3, but was inhibited in a dose-dependent fashion by ADP with a 50% inhibition occurring at 180 microM. Fifty mM MgCl2 was required for the maximal phosphorylation. The rate of phosphoprotein decomposition after adding 2 mM EGTA was accelerated by varying the Mg2+ concentration from 10 microM to 3 mM. Alkaline pH (9.0) slowed the rate of phosphoprotein decay. Optimal Ca2+-dependent phosphoprotein occurred at 15 degrees C over a broad pH range (6.4 to 9.0). The activation energy of EGTA-induced phosphoprotein decomposition was 25.6 kcal/mol between 0 and 16 degrees C and 14.6 kcal/mol between 16 and 30 degrees C. The phosphoprotein formed by aortic microsomes was thus quite similar to the acid-stable phosphorylated intermediate of the Ca2+-transport ATPase of sarcoplasmic reticulum from skeletal and cardiac muscle. These data suggest that the Ca2+-dependent phosphoprotein is a reaction intermediate of the Ca2+,Mg2+-ATPase of the aortic microsomes.

Adenosine Diphosphate↗
PubMed1984

Noninvasive evaluation of left ventricular function by systolic time intervals in essential hypertension with angina pectoris.

In order to clarify the hemodynamic characteristics in essential hypertension (HT) with angina pectoris (AP), systolic time intervals (STIs) were measured in 13 normal subjects (N), 23 patients with AP, 43 HT (WHO stage I: 13, WHO stage II: 23, WHO stage III: 7) and 19 HT with AP (WHO I: 9, WHO II: 10). The ET/PEP ratio was 2.41 +/- 0.24 in N, 2.70 +/- 0.34 in AP (p less than 0.02, vs N), 2.25 +/- 0.29 in WHO I, 2.13 +/- 0.25 in WHO II (p less than 0.01, vs N), 1.54 +/- 0.37 in WHO III (p less than 0.001, vs N), 2.68 +/- 0.32 in WHO I with AP (p less than 0.05, vs N: p less than 0.005, vs HT) and 2.71 +/- 0.30 in WHO II with AP (p less than 0.02, vs N: p less than 0.001, vs HT). Ejection time index (ETI) was 385 +/- 15 msec in N, 399 +/- 16 in AP (p less than 0.05, vs N), 387 +/- 13 in WHO I, 385 +/- 15 in WHO II, 363 +/- 25 in WHO III (p less than 0.05, vs N), 393 +/- 16 in WHO I with AP and 402 +/- 15 in WHO II with AP (p less than 0.05, vs N: p less than 0.01, vs HT). Pre-ejection period index (PEPI) was 142 +/- 10 msec in N, 135 +/- 11 in AP, 148 +/- 12 in WHO I, 156 +/- 13 in WHO II (p less than 0.005, vs N), 192 +/- 24 in WHO III (p less than 0.001, vs N), 134 +/- 13 in WHO I with AP (p less than 0.05, vs HT) and 136 +/- 9 in WHO II with AP (p less than 0.001, vs HT). These results showed that the ET/PEP ratio in HT with AP was significantly higher than that in HT alone, and this increase in ET/PEP ratio was mainly due to the shortening of PEP interval in WHO stage I and the lengthening of ET in addition to it in WHO stage II.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Syntheses of 23-deoxy-23-N-ethyl-23-(2-fluoro-, 2,2-difluoro-, and 2,2,2-trifluoroethyl)amino derivatives of mycaminosyl tylonolide and 4'-deoxymycaminosyl tylonolide.

Derivatives of mycaminosyl tylonolide (1) and 4'-deoxymycaminosyl tylonolide (2) containing N-ethyl-2-fluoro-, 2,2-difluoro- and 2,2,2-trifluoroethylamino groups at their C-23 have been prepared by treating 23-deoxy-23-ethylaminomycaminosyl tylonolide diethyl acetal (14) and its 4'-deoxy analog 15 with 2-fluoro-, 2,2-difluoro- and 2,2,2-trifluoroethyl trifluoromethanesulfonates. The relationship between the antibacterial activity and the numbers of the fluorine atoms introduced in the final products is discussed.

Leucomycins↗