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Biomedical subjects

T Mitsuoka

Publications and source records attributed to T Mitsuoka.

At least 145 records · Page 8Linked to original sources

Serogrouping of Bacteroides vulgatus by the agglutination test.

The agglutination technique was used to establish a serological classification scheme for Bacteroides vulgatus strains isolated from normal human feces and clinical specimens, especially from ulcerative colitis patients. Absorbed antisera to 10 strains of B. vulgatus were prepared. These 10 absorbed antisera were species specific. Of 90 B. vulgatus strains tested, 55 (61%) were agglutinated by one or more of these 10 absorbed antisera. A total of 27 serological patterns were grouped into 18 serogroups; 10 of these serogroups contained only one group component, whereas the other 8 serogroups were composed of more than one component. This serological classification could be used to study the epidemiology of this organism.

Adult↗

Comparison of media for isolation of mouse anaerobic faecal bacteria.

A study was made to determine suitable plate-in-bottle media for enumeration and isolation of the anaerobic faecal bacteria of mice. Comparison of non-selective media indicated that colony counts were higher on M-SM10, M10 and M-M98-5 than on EG, W & E medium and BHI, and those on M-SM10 were always the highest. Bacteroidaceae counts on M-SM10, M10, M-M98-5 were particularly high. On the other hand, in chloroform-treated faeces which contain only Clostridial spores, colony counts were higher on EG and W & E medium than on M-SM10, M10 and M-M98-5. These results indicate that suitable non-selective media vary according to the bacterial species to be enumerated and isolated.

Animals↗

Characteristic faecal flora of NC mice.

The composition of faecal flora of NC mice was compared with that of CF #1 mice. NC- and CF #1-germfree (GF) mice were cage-mated with NC- or CF #1-conventional (CV) mice in an isolator. The faecal flora of these ex-GF mice was dependent on the recipient mouse strain modifying colonization by the donor mouse bacteria. Although NC- and CF #1-pups removed by hysterectomy were fostered to different strains, almost all these mice at 8 weeks old had a strain characteristic pattern of faecal flora regardless of the foster strains. In GF mice mono-associated with a Lactobacillus strain or a Bifidobacterium strain isolated from faeces of CV mice, the numbers of these bacteria in the stomach and small intestine of NC mice were lower than those of CF #1 mice. In GF mice associated with chloroform-treated faeces of CV mice, and a Lactobacillus strain or a Bifidobacterium strain, the numbers of these bacteria in the stomach and all parts of the intestine of NC mice were considerably lower than those of CF #1 mice. These results suggested that the composition of faecal flora of NC mice were characteristic, i.e. the fact that the numbers of lactobacilli were low compared with CF #1 mice with ordinary faecal flora and the colonization of bifidobacteria, peptococcaceae and eubacteria on ES agar in NC mice intestine differed, was due to genetic factors.

Animals↗

Characterization of clostridia isolated from faeces of limited flora mice and their effect on caecal size when associated with germ-free mice.

115 strains of clostridia were accumulated from 3 separate isolations from the faeces of 1 limited flora (LF) mouse produced by inoculation of germ-free mice with chloroform-treated faeces of conventional mice. These strains were divided into 36 types on the basis of conventional biochemical characteristics. There was some variation in types isolated on the 3 occasions. Although 3 groups of polyassociated (PA) mice were produced from mixing 46 monoassociated mice, each inoculated with 1 of 46 strains of 36 bacterial types, the caecal size of PA mice was still greater than that of the control mice prepared by inoculation of chloroform-treated faeces of an LF mouse. After PA mice of each group were housed together, the caecal size became smaller and was only slightly larger than the control.

Acetates↗

Use of nonprotein nitrogen in pigs: effects of dietary urea on the intestinal microflora.

The fecal flora of 2 pigs given an optimal protein diet (digestive crude protein, 13.3%) with 2% urea, 2 pigs given a low protein diet (digestive crude protein, 5.7%) with 2% urea, and 2 pigs given a low protein diet only were bacteriologically investigated before feeding of each diet and on feeding days 21 and 38. The addition of urea to a low protein diet was significantly decreased Lactobacillus (P less than 0.001), Bacteroidaceae (P less than 0.01), Peptococcaceae (P less than 0.05), and Megasphaera (P less than 0.01) in the feces. In addition, there was a marked suppression of anaerobic curved rods (mainly Selenomonas) to undetectable amounts in the feces. A significant reduction (P less than 0.01) of Bifidobacterium and a marked suppression of Megasphaera to undetectable amounts were observed in the feces of pigs given low protein diets without urea. Microbial groups in the ileum and colon of pigs on feeding day 38 were also analyzed. Effects of dietary urea on the intestinal flora included: (i) anaerobic curved rods and spiral rods were restricted mainly to the colon, (ii) smaller numbers of yeasts were present in the intestine, and (iii) Bacteroidaceae, Peptococcaceae, and Eubacterium in the colon were not changed. Many anaerobic isolates, including curved rods and spiral rods, in the colon of pigs may have an important role in urea use.

Animals↗

Mechanism of polyuria and natriuresis in atrioventricular nodal tachycardia.

A woman with tachycardia associated with polyuria was investigated. Electrophysiological analysis showed that the tachycardia was an atrioventricular nodal re-entrant tachycardia. Programmed stimulation was then used to provoke and sustain the tachycardia for 40 minutes. Polyuria, with an appreciable increase in free water clearance, was observed. This was associated with reduction in plasma and urinary arginine vasopressin concentrations. Appreciable natriuresis also developed. These results support the hypothesis that the polyuria with increased free water clearance and the natriuresis occurring during sustained tachycardia in man are due to inhibition of secretion of vasopressin and the release of natriuretic factor.

Arginine Vasopressin↗

DNA methylation in chicken brain and liver.

Adult chicken brain DNA is subject to a developmental alteration of methylation at HpaII sites flanking 4, 1, 0.8 and 0.7 kilobase sequences. This change is not evident in adult chicken liver DNA and 1-day-old chick brain and liver DNAs, suggesting tissue specificity and age-dependency in DNA methylation.

Aging↗

[The effect of nutrition on intestinal flora].

In several groups of probands the influence of nutrition on the gut flora has been examined. In old people there is a striking decrease in the numbers of Bifidobacteria whereas those of Clostridium perfringens strongly increase and those of Enterobacteriaceae and Lactobacilli can be found somewhat higher than in the compared group. In a group of longevitial old aged men nourished with a fibre-rich diet these alterations are found less striking. Changing from a mixed Japanese diet to a "western diet" a tendentious decrease in the total number of bacteria and in the numbers of Bifidobacteria, Eubacteria, and in moderate, in the numbers of Streptococci, too, could be determined. Simultaneously, a considerable development of nitrosamines occurred. In C3H/Hemice a glucomannan containing (fibre-rich) diet caused a substantial increase in the evidence frequency of Bifidobacterium and in the numbers of Enterobacteriaceae. Parallel with these results incidence and average number of noduli of manifested hepatic carcinoma decreased remarkably.

Adult↗

Spontaneous polyposis in the small intestine of germ-free and conventionalized BALB/c mice.

The spontaneous polyposis in the small intestine of germfree (Gf) and conventionalized (Cv) BALB/c mice was studied. Gf mice were bred in our laboratory and maintained Gf in vinyl isolators. The first generation offspring of the Cv mice derived from the Gf mice was used as Cv animals. When they were 12 months old, the animals were killed under CO2 inhalation and autopsied carefully for the number and size of polyps with the aid of a dissecting microscope. The incidence of polyposis was higher in the Gf mice (68% in female and 89% in male) than in the Cv mice (37% in female and 51% in male). The number of polyps/mouse was also higher in the Gf mice (2.3 in female and 5.7 in male) than in the Cv mice (0.8 in female and 1.3 in male). All of the polyps were histopathologically adenomatous and developed only in the upper part (mainly duodenum) of the small intestine. The present study demonstrated that development of polyposis in the small intestine of BALB/c mice was suppressed by the presence of intestinal microflora.

Animals↗

The intestinal microflora of infants: composition of fecal flora in breast-fed and bottle-fed infants.

The fecal flora of 35 breast-fed and 35 bottle-fed babies was determined. Bifidobacteria were the predominant fecal bacteria in both groups. Conversely, the counts of most of the other bacteria, such as bacteroides, eubacteria, peptococci, veillonella, clostridia, enterobacteria, streptococci, and bacilli in the bottle-fed group were significantly higher than those in the breast-fed group. The frequencies of occurrence of lecithinase positive clostridia, clostridia-others, pseudomonas and bacilli in the bottle-fed group were significantly higher than those in the breast-fed group. Twenty-one genera and 103 species or biovars of microorganisms were isolated from the feces of the breast-fed group and 20 genera and 97 species or biovars from the bottle-fed group. The organism that showed the highest number and the highest frequency of occurrence in both groups was Bifidobacterium breve. Bifidobacterium infantis, which was formerly the most prevalent Bifidobacterium species in baby feces, was never isolated in this study. Further, the counts and incidences of Clostridium paraputrificum, C. perfringens, and Bacillus subtilis, the counts of C. clostridiiforme, Bacteroides vulgatus, Veillonella parvula, Lactobacillus acidophilus, Escherichia coli, Streptococcus bovis, S. faecalis, and S. faecium and the incidences of C. difficile, C. tertium, and Pseudomonas aeruginosa in the bottle-fed infants were significantly higher than those in the breast-fed infants.

Bacteria↗