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Biomedical subjects

M Mayama

Publications and source records attributed to M Mayama.

At least 19 recordsLinked to original sources
PubMed1990

[A markedly effective combination therapy of 5'-DFUR and MMC in advanced gastric cancer--a case report].

We performed a combination therapy with two drugs, 5'-DFUR and MMC, which proved to be markedly effective in one patient. The patient was 73-year-old female with tumor, advanced cancer gastric lower third portion. Borrmann type 3, an poorly differentiated adenocarcinoma. Since the patient rejected an operation, the drug therapy was selected. Oral administration of 5'-DFUR 800 mg daily was combined with intermittent intravenous administration of mitomycin C. In 3 years, the cancerous site got scarred and no distant metastasis was observed. Presently, she feels well, receiving an outpatient treatment.

Adenocarcinoma↗
PubMed1982

Asparenomycins A, B and C, new carbapenem antibiotics. IV. Antibacterial activity.

Asparenomycins (ASM) A, B and C, new members of the carbapenem family of antibiotics, are broad spectrum antibiotics with activity against Gram-positive and Gram-negative bacteria. ASM A was bactericidal to both aerobic and anaerobic bacteria, although morphological alterations of ASM A exposed cells differed significantly between Escherichia coli and Bacteroides fragilis; with the former ovoidal forms were produced while with the latter elongated forms were seen. Synergistic activities were observed with a combination of ASM A and ampicillin (ABPC) against various ABPC-resistant bacteria presumably as a result of the inhibition by ASM A of beta-lactamases. ASM A showed relatively weak therapeutic activity against E. coli infected mice, because of instability in body fluids, a common property of the carbapenem family of antibiotics.

Animals↗
PubMed1981

Isolation of N-(2,6-diamino-6-hydroxymethylpimelyl)-L-alanine from Micromonospora chalcea.

A novel dipeptide, N-(2,6-diamino-6-hydroxymethylpimelyl)-L-alanine, was isolated from the culture broth of a microorganism identified as Micromonospora chalcea. The dipeptide exhibits antimicrobial activity against Escherichia coli on a synthetic medium, and the activity is synergistically enhanced by several cell wall synthesis-inhibitors.

Amino Acids, Diamino↗
PubMed1981

Water-soluble siomycin-A derivatives. Preparation, chemical structures and biological properties of half-esters of the peptide antibiotic.

The peptide antibiotic siomycin-A was transformed into half-esters with dicarboxylic acids with the intention of making siomycin-A soluble in water. Sodium salts of the half-esters were also prepared. Some of the salts showed antibacterial activities comparable to siomycin-A against Gram-positive bacteria in vitro and exhibited better therapeutic effects in infected mice than siomycin-A. The chemical structures of siomycin-A hemiadipate-II and -III were elucidated by comparing their 13C and 1H NMR spectra with those of siomycin-A. Their physicochemical properties are described.

Animals↗
PubMed1980

Moxalactam (6059-S), a novel 1-oxa-beta-lactam with an expanded antibacterial spectrum: laboratory evaluation.

Moxalactam (6059-S) {7beta-[2-carboxy-2-(4-hydroxyphenyl)acetamido]-7alpha-methoxy-3-[[(1-methyl-1H-tetrazol-5-yl)thio]-methyl]-1-oxa-1-dethia-3-cephem-4- carboxylic acid disodium salt} is a new semisynthetic 1-oxa-beta-lactam derivative for parenteral use. It was highly active against a broad range of gram-negative microorganisms, including those resistant to other cephalosporins. Moreover, it had widely expanded antibacterial spectra which included Haemophilus influenzae, indole-positive Proteus, Enterobacter, Serratia marcescens, Pseudomonas aeruginosa, and Bacteroides fragilis. When a large number of clinical isolates of the above-named bacilli were tested by the agar dilution method, using an inoculum size of one loopful of 10(6) or 10(8) organisms or both per ml, the 70% minimal inhibitory concentrations at the lower inoculum were 0.2, 0.2, 0.4, 0.8, 25, and 0.8 mug/ml, respectively. Its activity appeared to be independent of inoculum size and addition of serum. In these organisms, morphological response of the exposed cells revealed that the bacteriolytic effect of 6059-S was initiated by a concentration equivalent to the minimal inhibitory concentration. 6059-S was markedly bactericidal to both beta-lactamase-producing and -nonproducing strains of Escherichia coli; this was well reflected by its extraordinary stability to microbial beta-lactamase degradation. Administered subcutaneously in mice, 6059-S attained plasma levels and a half-life similar to those of cefazolin and exhibited potent protective efficacy against systemic infections; it also proved to be significantly more effective than either sulbenicillin or piperacillin against Pseudomonas aeruginosa and than either cefazolin or cefmetazole against a variety of other gram-negative bacteria.

Animals↗
PubMed1980

Isolation of octapeptin D (studies on antibiotics from the genus Bacillus. XXVII).

A new peptide antibiotic complex, named octapeptin D, was isolated from culture broth of a microorganism belonging to the genus Bacillus. The trihydrochloride of the antibiotic was obtained as a colorless powder, soluble in water and methanol. The empirical formula, C47H88N12O11.3HCl.H2O, was indicated by elemental analysis. Amino acid analysis on the acid hydrolyzate demonstrated the presence of 2,4-diaminobutyric acid (4 moles), serine (1 mole) and leucine (3 moles). Gas chromatographic analysis with the methylated product of the ethereal extract of the acid hydrolyzate revealed the presence of beta-hydroxy isodecanoic acid, beta-hydroxy decanoic acid, beta-hydroxy isoundecanoic acid and beta-hydroxyanteisoundecanoic acid. Octapeptin D is active against Gram-negative and Gram-positive bacteria in vitro and in vivo.

Animals↗
PubMed1978

[In vitro antibacterial activity of tobramycin used in combination with cephalothin or carbenicillin (author's transl)].

Combinations of tobramycin (TOB) with cephalothin (CET) or carbenicillin (CBPC) were evaluated by in vitro test against 161 clinical isolates of Klebsiella pneumoniae, Escherichia coli, indole-positive Proteus, Enterobacter and Serratia marcescens which were not inhibited by 6.25 microgram/ml of CET. The combinations were considered to show synergy when there was a 4-fold or greater reduction in MIC values (FIC index less than or equal to 0.5) of both antibiotics when combined. Synergy of TOB with CET could be demonstrated against 83% of Klebsiella pneumoniae, 78% of E. coli, 44% of Proteus rettgeri and 39% of Proteus inconstans. Synergy of TOB with CBPC could be demonstrated against 78% of Proteus vulgalis, 45% of Serratia marcescens and 28% of Proteus inconstans. Bactericidal effect showing synergy of TOB with CET could be demonstrated against each 2 strains of Klebsiella pneumoniae and E. coli. Frequency of synergy of TOB with CET under the condition of large inoculum size was significantly higher than that of synergy of TOB with CET under the condition of small inoculum size. Synergy of bactericidal effect of TOB combined with CET against Klebsiella pneumoniae and E. coli was more active when they were combined at the same time, than those of when TOB was combined after 2 hours exposure by CET or when CET was combined after 2 hours exposure by TOB. No antagonistic action was observed in these studies.

Anti-Bacterial Agents↗
PubMed1977

Isolation of two new polymyxin group antibiotics. (Studies on antibiotics from the genus Bacillus. XX).

Two new members of polymyxin group antibiotics, polymyxins S1 and T1, were isolated from the culture broths of strains identified as Bacillus polymyxa Rs-6 and Bacillus polymyxa E-12, respectively. These antibiotics are strongly basic substances, their hydrochloric acid salts are soluble in water and methanol. They are primarily active against Gram-negative bacteria in vitro and in vivo though polymyxin T1 exhibits higher activities against Gram-positive bacteria than other polymyxin group antibiotics.

Bacillus↗
PubMed1976

Production and isolation of cerexins C and D studies on antibiotics from the genus Bacillus. XVII.

From the culture broth of Bacillus cereus 60-6, in which antibiotic production was improved a new antibiotic, named cerexin C, was isolated. Similarly, a new antibiotic, cerexin D was isolated from the culture broth of Bacillus cereus Gp-3. Cerexins C and D are closely related to cerexins A and B in their physico-chemical and antimicrobial properties. In fact cerexins C and D are peptides essentially identical with cerexins A and B except for the presence of a lysine residue in place of the gamma-hydroxylysine residue.

Amino Acids↗
PubMed1976

Isolation of three new antibiotics, thiocillins I, II and III, related to micrococcin P. Studies on antibiotics from the genus Bacillus. VIII.

Thiocillins I and II were isolated from the culture broth of Bacillus cereus G-15, and thiocillins II and III from that of Bacillus badius AR-91. Also, the former two were probably produced by Bacillus megatherium I-13. These antibiotics active against Gram-positive bacteria are soluble in a mixture of chloroform and methanol, show characteristic ultraviolet absorptions (maxima at ca. 275 nm and ca. 348 nm), and contain a high content of sulfur, as much as approximately 15%. They are related to each other and also to micrococcin P, but differentiated by chromatographic behaviours.

Animals↗
PubMed1976

Isolation of brevistin, a new peptide antibiotic. Studies on antibiotics from the genus Bacillus. IX.

A new peptide antibiotic, brevistin, was isolated from the culture broth of Bacillus brevis 342-14. Brevistin is an acylpeptide with an approximate empirical formula of C63H91N15O18 containing aspartic acid, threonine, glycine, valine, isoleucine, phenylalanine, tryptophan and 2,4-diaminobutyric acid. The antibiotic is soluble in acid and alkaline water. Its hydrochloride is soluble in methanol. Brevistin is active against Ggam-positive bacteria in vitro and in vivo, and is of low toxicity to mice.

Animals↗
PubMed1976

Isolation of a new antibiotic, laterosporamine. Studies on antibiotics from the genus Bacillus. XIII.

A new antibiotic, named laterosporamine, was isolated from the culture broth of Bacillus laterosporus 340-19. The antibiotic is active against Gram-positive and Gram-negative bacteria in vitro and in vivo. It is a water-soluble basic substance, positive to ninhydrin, SAKAGUCHI'S and DRAGENDORFF'S reagents. A non-peptidic structure with an approximate empirical formula C17H35N7O4 was suggested.

Animals↗