Search PubMed⌕ Search

Biomedical subjects

T Mitsuoka

Publications and source records attributed to T Mitsuoka.

At least 181 records · Page 10Linked to original sources
PubMed1980

Amounts of intestinal microflorae in relation to colon carcinogenesis. An experimental study.

Quantitative analysis of intestinal microflorae in the diverted and feces-containing portions of the colon after performing an ascendo-descendostomy Roux en Y in Wistar-Lewis rats, the colonic portion from the ascending colon to the midportion of the descending colon being diverted from the fecal stream, disclosed a drastic decrease in the total amount of the intestinal microflora as well as most anaerobic microflorae in the diverted portion of the colon where the amount of the colonic content was extremely reduced. This diverted segment was least susceptible of developing macroscopical epithelial neoplasia after exposure to a carcinogen, MNNG, sufficient in amount to evoke multiple large neoplasia in the ordinary colon, although microscopical intramucosal neoplastic foci were induced there. Thus the existence of the intestinal content was essential for the process of promotion in experimental colonic carcinogenesis. The close parallelism between amounts of intestinal content and amounts of intestinal microflorae, especially anaerobic ones, suggested the roles of anaerobic microflorae in colonic carcinogenesis.

Anaerobiosis↗
PubMed1980

Inhibitory effect of some intestinal bacteria on liver tumorigenesis in gnotobiotic C3H/He male mice.

Liver tumorigenesis in gnotobiotic C3H/He male mice was markedly promoted by association with a bacterial combination of Escherichia coli, Streptococcus faecalis, and Clostridium paraputrificum. This study demonstrated that this promoting effect was suppressed by addition of certain intestinal bacteria, such as Bifidobacterium longum, Lactobacillus acidophilus, and Eubacterium rectale.

Actinomycetaceae↗
PubMed1980

Streptococcus faecium-derived antibacterial substance antagonistic to Bifidobacteria.

An antagonistic strain of Streptococcus faecium was isolated from human feces, and it displayed a marked inhibition of bifidobacteria on agar plates. In liquid culture this isolate produced an antibacterial substance that can be partially purified by ammonium sulfate precipitation followed by gel filtration and ion-exchange chromatography. Its activity was assayed by the inhibition of growth of Bifidobacterium longum. The substance was sensitive to digestion by proteolytic enzymes and alpha-amylase, but was resistant to treatment with 6 M urea, dithiothreitol, 2-mercaptoethanol, ethyl ether, chloroform, and lysozyme. It was also stable to heating at 100 degrees C for 60 min. Its molecular weight was estimated to be about 50,000 by gel filtration.

Actinomycetaceae↗
PubMed1980

Utilization of ammonia nitrogen by intestinal bacteria isolated from pigs.

In a medium containing ammonia, proteose peptone, and cysteine as nitrogen sources, 17 of 24 Bacteroidaceae strains, 3 of Selenomonas strains, 1 of 7 curved rods, 3 of 7 Spirochaetaceae strains, 8 of 20 Eubacterium strains, 8 of 13 Peptococcaceae strains, 3 of 4 Clostridium strains, 19 of 20 Enterobacteriaceae strains, and 1 of 8 Streptococcus strains utilized ammonia nitrogen preferentially to proteose peptone nitrogen. To determine the ability of intestinal microbes to synthesize amino acids from ammonia, ammonia utilization by Bacteroides ruminicola strain 9 was studied in defined media containing ammonia and other nitrogen sources. In another medium containing ammonia, proteose peptone, and cysteine as nitrogen sources, ammonia was preferentially utilized even when the proteose peptone nitrogen content was eight times greater than that of ammonia nitrogen. In a medium containing ammonia, an amino acid, and cysteine, the lowest uptake of ammonia nitrogen was observed when the medium contained aspartic acid, glutamic acid, threonine, or alanine; but ammonia was utilized more effectively than any of the amino acids. Incorporation of (15)N from [(15)N]ammonia into bacterial amino acids was studied. (15)N was incorporated into every amino acid of B. ruminicola strain 9, and the highest uptake was observed in aspartic acid and alanine.

Amino Acids↗
PubMed1979

Urease-producing species of intestinal anaerobes and their activities.

Urease activities of anaerobic bacteria that constituted predominant gut flora were examined. It was demonstrated that some strains of Eubacterium aerofaciens, E. lentum, and Peptostreptococcus products produced urease. They were the most numerous species in human feces. All strains of Bifidobacterium infantis and some strains of Bacteroides multiacidus, B. bifidum, Clostridium symbiosum, Fusobacterium necrophorum, F. varium, Lactobacillus fermentum, Peptococcus asaccharolyticus, and P. prevotii produced urease. The optimum pH of the Lactobacillus urease was found to be 4.0, whereas the pH value of B. multiacidus urease was 8.0.

Anaerobiosis↗
PubMed1979

Effect of intestinal bacteria on incidence of liver tumors in gnotobiotic C3H/He male mice.

The effect of intestinal microflora on liver tumorigenesis was studied in gnotobiotic C3H/He male mice monoassociated, diassociated, or polyassociated with the following strains of intestinal bacteria: Escherichia coli, Streptococcus faecalis, Bifidobacterium adolescentis, Bifidobacterium infantis, Clostridium indolis, C. paraputrificum, C. perfringens, C. innocuum, C. nexile, C. ramosum, C. clostridiiforme, Bacteroides multiacidus, Bacteroides fragilis, Veillonella alcalescens, V. parvula, and Lactobacillus acidophilus. The incidence of liver tumors was higher in most of the gnotobiotes (67--100%) and conventionalized mice (82%) derived from the germfree mice than in the germfree mice (39%). The average incidence of tumor nodules in gnotobiotes associated with E. coli, S. faecalis, and C. paraputrificum was 2.9, which was significantly higher than that in the conventionalized animals (1.6). In contrast, the average incidence of tumor nodules in gnotobiotes associated with E. coli, S. faecalis, L. acidophilus, C. perfringens, and Bacteroides fragilis (0.9) was not significantly different from that in germfree animals (0.5). The present study demonstrated that the presence of certain intestinal bacteria is related to liver tumorigenesis in gnotobiotic C3H/He male mice.

Animals↗
PubMed1978

Primary aldosteronism aggravated during peripartum period.

Two cases are reported of a 30-year-old and of a 28-year-old Japanese women with primary aldosteronism in whom metabolic and blood pressure abnormalities were aggravated during peripartum period. The characteristic findings in 2 present cases are as follows; 1) lower blood pressure during pregnancy, 2) elevated blood pressure during peripartum period, and 3) after parturition, serum potassium decreased, and the blood pressure elevated. The reason why the hypertension and hypokalemia associated with primary aldosteronism were ameliorated during pregnancy was thought to be due to the increased secretion of progesterone. Furthermore, the rapid recurrence of symptoms, increase in blood pressure, and hypokalemia in the post-partum period could be related to elevated prolactin and decreased progesterone levels.

Adenoma↗
PubMed1978

[An autoclavable stainless steel isolator for small scale gnotobiotic experiments (author's transl)].

A lightweight stainless steel autoclavable pentagon isolator was designed for experiments using gnotobiotic mice. The chamber, 400 x 450 x 350 mm, has an entry port 200 mm in diameter at the back and a window at the ceiling. The globes and two filters were equipped at the front and each side, respectively. An inner stainless steel cap of the entry lock was sealed by a seamless silicone band. It was possible to ventilate this isolator by either free-flow or blower operation. After autoclaving the isolators 10 to 16 times for a year, none of them was repaired. Five mice can be kept in this isolator for about 1 month without supply of diet, water and wood shaving after the first setting.

Animals↗
PubMed1977

[Fecal flora of man. V. communication: The fluctuation of the fecal flora of the healthy adult (author's transl)].

Seven fecal specimens from each of healthy persons, aged 25 to 42 years, during the period of 2 months were analyzed to obtain the knowledge on the day-to-day variation in the same person and the person-to-person variation. Irrespective of individuals, bacteroidaceae, catenabacteria (eubacteria and strict anaerobic lactobacilli), peptostreptococci (anaerobic gram positive cocci) and bifidobacteria constituted the predominant flora. Spirillaceae, megasphaerae and clostridia (except Cl. perfringens) were also found as predominant flora in specific individuals. In all cases, enterobacteria and streptococci constitute the accompanying flora. In addition, veillonallae and lactobacilli were found as predominant flora in most cases. The remaining flora, consisting of Cl. perfringens, staphylococci and yeast, occurred occasionally in low numbers. With regard to the composition of the fecal flora of each person, a great individual variation was recognized and confirmed statistically. Each person had a characteristic fecal flora. In the same person, the numbers of bacteria of the predominating flora were over a 2 months period relatively constant. On the other hand, a great day-to-day variation in the numbers of bacteria of the accompanying flora as well as the remaining flora was demonstrated.

Adult↗
PubMed1976

Microorganisms responsible for controlling the populations of Escherichia coli and enterococcus and the consistency of cecal contents in the chicken.

A study was made to clarify what kinds of intestinal organisms might be responsible for controlling the populations of Escherichia coli and Streptococcus faecalis var. liquefaciens in the cecum and the consistency of the cecal of chickens. Germ-free chickens were inoculated orally with various mixtures of bacterial cultures alone or in combination, different dilutions of the cecal contents of chickens, different dilutions of the cecal contents treated by healing or with chloroform, the supernatant of diluted cecal contents, and dilutions of human feces. Factors controlling the E. Coli populations, enterococcal populations, and consistency of the cecal contents were shown to be independent of one another. The ecosystem controlling the E. coli or enterscoccal population was more complex than that controlling the consistency of the cecal contents. The former was composed of anaerobic and facultatively anaerobic bacteria isolated and heat- or chloroform-resistance organisms, and the latter of heat- or chloroform-resistance alone, which were inferred not to prevailing in the cecal contents of chickens. Discussion is made on ecological systems controlling flora.

Animals↗
PubMed1976

[The fecal flora of man. IV. Communication: Comparison of the newly developed method with the old conventional method for the analysis of intestinal flora (author's transl)].

The results of 42 fecal flora analysis of healthy adult men were compared by using a newly developed method and an old conventional method. Statistical estimate indicate, that with the new method the total counts and the counts of bifidobacteria, catenabacteria (eubacteria and anaerobic lactobacilli), peptostreptococci, and clostridia (except Cl. perfringens) as well as the occurences of peptostreptococci and spirillaceae were significant higher than with the use of the old method. On the other hand the counts and occurences of bifidobacteria, veillonellae, Cl. perfringens, Megasphaerae and aerobes were similar with both method. With the new method the total counts of feces of healthy adult men nubmered 1-2 X 10(11) per g wet weight, and fastidious anaerobes, such as bacteroides, catenabacteria and peptostreptococci, were always occurred as predominant flora. The results suggest that the conventional anaerobic jar method is inadequate for the isolation of fastidiuos anaerobes and indicate that the use of modified medium 10 in combination with strict anaerobic technique is necessary for the analysis of fecal flora.

Adult↗