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Biomedical subjects

K Yazawa

Publications and source records attributed to K Yazawa.

At least 199 records · Page 11Linked to original sources
PubMed1980

Increased production of saframycin A and isolation of saframycin S.

This paper reports on an increased production of saframycin A, which is a satellite antibiotic to streptothricin and a trace component in the culture of Streptomyces lavendulae No. 314. Some improvement in the yield of the antibiotic was attained by supplementing the standard medium with two end-products of metabolic pathways related to saframycin biosynthesis. A further significant increase of saframycin A potency could be attained by addition of NaCN to the culture broth. Finally, a drastic degradation of saframycin A in the culture was successfully prevented by maintaining the pH lower than 5.5 after peak production of the antibiotic. The combined application of these improvements resulted in approximately 1,000-fold increase in saframycin A production as compared with the parental level. The precursor of saframycin A in the culture, which yielded saframycin A upon cyanation was isolated, characterized and named saframycin S. Physicochemical properties of saframycin S were described and structural formulae were discussed.

Anti-Bacterial Agents↗
PubMed1978

Interactions between Bifidobacterium bifidum N4 and Escherichia coli K-12 in their mixed cultures.

The interactions between Bifidobacterium bifidum N4 (B. bifidum) and Escherichia coli K-12 (E. coli) were investigated in their mixed cultures. Under conditions in which both bacteria grew well in their pure culture, B. bifidum inhibited the growth of E. coli even when the latter was inoculated at 10(4)-fold and preincubated for 41 hr. The inhibition in the mixed cultures appeared when the pH values were reduced below 4.6. When the lowering of pH was prevented by the addition of NaOH, no inhibition was observed. At the same initial pH of 6.5, lactic acid and acetic acid, metabolites of B. bifidum, had more inhibitory effect on the growth of E. coli than other aliphatic fatty acids. On the other hand, in the mixed cultures with E. coli, B. bifidum grew in the absence of its essential vitamins, riboflavin and pantetheine and, furthermore, aerobically.

Acetates↗
PubMed1976

Vaginal repair in the radical operation for cervical carcinoma.

An attempt was made to preserve postoperative sexual function and the recovery of bladder function by a simple modification of technique in 22 cases of radical operations for invasive carcinoma of the cervix. The procedures consisted of two parts. After removal of the specimen, the bladder peritoneal flap is sutured to the anterior vaginal wall leaving a 2 to 3 cm margin between the line of suture and the edge of the peritoneum. Similarly, the posterior peritoneal flap is sutured to posterior vaginal wall leaving a margin. Both edges of the peritoneum are then closed forming a pouch as an extension of vaginal canal. The length of the vagina was successfully elongated by this procedure, thus adding to better postoperative sexual function.

Female↗
PubMed1976

Isolation and characterization of satellite antibiotics, mimosamycin and chlorocarcins from Streptomyces lavendulae, streptothricin source.

Under novel conditions of culture, Streptomyces lavendulae No. 314 was found to produce new antibiotics, chlorocarcins and mimosamycin in addition to streptothricin. The antibiotics are extracted from culture filtrate with organic solvents and further purified by silica gel chromatography. Chlorocarcins A, B and C are closely related basic antibiotics which are active against gram-positive bacteria, EHRLICH carcinoma and L 1210 leukemia of mice. Mimosamycin is a neutral antibiotic which is mainly active against mycobacteria. Production, isolation and physicochemical properties of the antibiotics are described.

Animals↗
PubMed1975

Site of ovulation and ectopic pregnancy.

In a study of 130 tubal pregnancies the relationships as to location of the corpus luteum, the implantation site, and the gross findings of the non-pregnant fallopian tube were analyzed. A contralateral corpus luteum was found in 20% of the cases. Hydrosalpinx, peritubal adhesions and/or thickening of the tubal wall were observed in 33% of the non-pregnant tubes. Grouping by implantation site--ipsilateral or contralateral corpus luteum--showed no statistical differences. The incidence of chronic pelvic inflammatory diseases was no greater in the subjects above 30 years of age and those having had more than 2 pregnancies. The results suggest that "tube locking" of the ovum, sometimesa result of previous tubal inflammatory disease, sometimes a result of supposed insufficiency of tubal peristalsis. was the major cause of tubal gestation. External migration of the ovum alone may not be an important factor in the genesis of tubal pregnancy.

Adult↗