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Biomedical subjects

T Mitsuoka

Publications and source records attributed to T Mitsuoka.

At least 37 records · Page 2Linked to original sources

Effect of standing on ventricular parasystole: shortening of the parasystolic cycle length.

OBJECTIVE: To investigate the effect of standing on the parasystolic cycle length in cases of "true" ventricular parasystole. METHODS: Parasystolic cycle length and sinus cycle length were measured during lying and standing in eight men with true ventricular parasystole. These cycle lengths were also measured after exercise in the lying position. RESULTS: In all cases, parasystolic cycle length and sinus cycle length both shortened on standing, by a mean of 6.4% and 17.8%, respectively, compared to lying. In all cases, the rate of shortening of the parasystolic cycle length was less than that of the sinus cycle length. Parasystolic cycle length was prolonged after exercise, in contrast to a shortening of the sinus cycle length. CONCLUSIONS: Influences on the parasystolic cycle length are not always in the same direction as on the sinus cycle length. This suggests that the effect of autonomic changes on parasystolic rhythm is not always parallel to that on sinus rhythm.

Adolescent↗

Factors influencing the development of sigmoid colon cancer. Bacteriologic and biochemical studies.

BACKGROUND: Cancer of the sigmoid colon is especially sensitive to environmental factors such as food. The authors have conducted a series of studies with food as the external environmental factor and intestinal microflora as the internal environment factor in relation to sigmoid colon carcinogenesis. METHODS: Thirteen males who had previously undergone surgery for sigmoid colon cancer, and who later developed new epithelial neoplasia of the colon, were chosen as the high risk (HR) group. Fourteen males of similar age, whose large bowel was entirely normal by total colonoscopy, were chosen as the control (CONT) group. Food constituents were analyzed by a dietician. Fecal bile acids, cholesterol metabolites, degradation products of amino acids, pH, water content, and bacterial flora were quantitatively analyzed. RESULTS: Although the HR group consumed slightly more carbon hydrate, fiber, and calcium, as a whole, there was no significant difference in food constituents, especially animal fat, between the two groups. Concentrations of bile acids and cholesterol metabolites were not different between the groups, with the exception of a higher level of cholestanol in the HR group. Succinic, lactic, propionic, and isovaleric acids were abundant in the HR group. Fecal pH and amounts of hydrogen sulfide and cresol also were higher in the HR group. The total amount of bacteria, lecithinase-negative Clostridia, and Lactobacillus, were also more abundant in the HR group. CONCLUSIONS: The feces of the HR group was abundant in such substances as sigmoid colon cancer promoters, and appeared unrelated to food constituents. Resident flora of the HR group were abundant in enzymatically active anaerobes. Because agents carcinogenic to the colon and rectum exist ubiquitously, microflora play a key role in sigmoid colon carcinogens by producing promoters.

Aged↗

Reverse effects of exercise on the sinus and parasystolic cycle lengths.

Ventricular arrhythmias are the primary concern in the exercise laboratory. It has recently been suggested that in not a few cases, ventricular premature complexes are governed by modulated parasystole and not by ordinary extrasystolic rhythm. In many cases, however, it is difficult to differentiate between parasystole and ordinary extrasystoles. Few reports are available on the effect of exercise in cases of "true" parasystole. This study investigated the effect of exercise on the parasystolic cycle length 11 cases of true ventricular parasystole, in which one or more "pure" parasystolic cycles containing no intervening nonectopic QRS complexes were found. In all cases, in contrast to an acceleration of the sinus rate, a definite decrease in the parasystolic rate was found. In no case did complete suppression occur. These findings suggest that the effects of exercise on ordinary ventricular extrasystolic rhythm and on ventricular parasystole may be considerably different from each other.

Adult↗

Homofermentative Lactobacillus species predominantly isolated from canine feces.

Lactobacillus salivarius group biovars VIa and VIb, which are homofermentative Lactobacillus, were predominantly isolated from canine feces. Identification and biotyping of L. salivarius group biovars VIa and VIb were originally done by Mitsuoka et al. (1976). These strains were tentatively identified as L. salivarius by their phenotypic characteristics. They are, however, more similar to those of some new Lactobacillus species, particularly L. animalis and L. murinus, than those of L. salivarius and have now been identified as L. animalis by DNA-DNA homology.

Animals↗

Arthroscopic repair for a flap tear of the posterior horn of the lateral meniscus adjacent to its tibial insertion.

A flap tear of the posterior horn of the lateral meniscus adjacent to its tibial insertion combined with acute rupture of the anterior cruciate ligament was successfully repaired arthroscopically by a combination of advancement of the tip of the flap into a drill hole created in the tibia and an inside-out stacked suture technique using Henning instrumentation in two cases. However, the long-term function of the repaired menisci, which was reduced several millimeters in circumferential length, is still unknown.

Adolescent↗

New selective media for isolation of clostridia from faecal specimens.

Two selective media, novobiocin-colistin agar (NCA) and colistin-crystal violet agar (CCA), were developed for isolating clostridia from human and animal faeces. The basal medium was modified Eggerth-Gagnon agar. The NCA medium contains novobiocin (8 micrograms ml-1) and colistin (8 micrograms ml-1) and the CCA medium contains colistin (10 micrograms ml-1) and crystal violet (10 micrograms ml-1). Nine faecal specimens were cultured. Clostridia isolated on these media were similar to those on non-selective media, and higher than those isolated after heat treatment. However, more clostridial species were isolated on the new selective media compared with the non-selective medium. These selective agars were particularly useful for enumerating and isolating clostridia from human faeces.

Animals↗

Effect of tea polyphenols on fecal flora and fecal metabolic products of pigs.

The effects of tea polyphenols on fecal flora and fecal metabolic activities were studied in eight 30-day-old pigs fed a basal diet (control) or the diet supplemented with 0.2% of tea polyphenols for 2 weeks. During tea polyphenol administration compared to before administration, the levels of lactobacilli were increased significantly (P < 0.05 and P < 0.01 on days 7 and 14 of administration, respectively), whereas the levels of total bacteria (P < 0.01) and bacteroidaceae (P < 0.01 and P < 0.001 on days 7 and 14 of administration, respectively) were decreased significantly. The detection rate of lecithinase positive clostridia including Clostridium perfrigens showed a tendency to decrease during administration. No detectable change occurred in the levels of other organisms throughout the experimental period. Fecal concentrations of ammonia were decreased significantly (P < 0.05 and P < 0.01 on days 7 and 14 of administration, respectively). Fecal phenol (P < 0.001), p-cresol (P < 0.05), and skatol (P < 0.01) were reduced significantly on day 14 of administration compared to before administration. The amounts of fecal short chain fatty acids, acetic acid (P < 0.05) and lactic acid (P < 0.05) were increased significantly on day 14 of administration. The pH values were decreased slightly during administration. The odour of the feces was reduced remarkably during tea polyphenol administration.

Animals↗

Development of intestinal flora of human-flora-associated (HFA) mice in the intestine of their offspring.

Development of intestinal flora in newborn human-flora-associated (HFA) mice was compared with that in newborn conventional (CV) mice. Facultative anaerobes were detected from the first day after birth in both CV and HFA mice but anaerobes were not detected in the first week. Anaerobes rapidly increased from the 2nd week after birth and became predominant in newborn intestine. Most of the intestinal bacteria in adult CV and HFA mice were colonized in the intestine of CV and HFA mice, respectively, within 3 weeks after birth. The human intestinal flora established in the intestine of HFA mice finally reproduced without any remarkable change in composition in the intestine of newborn HFA mice. The development of intestinal flora in HFA mice was similar to that in CV mice but not that in human infants. These results indicated that human flora associated in HFA mice could be transferred from mothers to their offspring although HFA mice could not simulate the development of intestinal flora of the human infant.

Adult↗

Effects of dietary supplementation with lactosucrose (4G-beta-D-galactosylsucrose) on cecal flora, cecal metabolites, and performance in broiler chickens.

The effects of dietary lactosucrose on cecal flora, cecal metabolites, and performance were studied in eight 20-d-old and eight 62-d-old broiler chickens fed a basal diet (control) or a diet with .15% lactosucrose added. On Day 20 of age, the frequency of occurrence of lecithinase-negative clostridia were decreased (P < .05) by lactosucrose consumption. On Day 62 of age, the numbers of bifidobacteria were increased (P < .05) by lactosucrose consumption, but the counts of lecithinase-positive clostridia, including Clostridium perfringens, bacteriodaceae, and staphylococci, total anaerobic bacteria, and the frequency of occurrence of pseudomonads were decreased (P < .05). No detectable change was observed in counts of other organisms throughout the experimental period. Cecal concentration of ammonia (P < .01), phenol (P < .05), and cresol (P < .05) were decreased on Day 62 of lactosucrose consumption. Acetic acid and butyric acid were increased (P < .01 and P < .05, respectively) on Day 62 of lactosucrose consumption. Environmental ammonia and odor of chicken ceca were greatly reduced by lactosucrose consumption.

Ammonia↗

Effect of lactosucrose (4G-beta-D-galactosylsucrose) on fecal flora and fecal putrefactive products of cats.

The effects of lactosucrose (4G-beta-D-galactosylsucrose) on fecal flora and fecal putrefactive products were studied in 3 Himalayan and 5 Persian cats fed 175 mg of lactosucrose/each/day for 2 weeks. During lactosucrose administration, the counts of lactobacilli increased significantly (p < 0.05), whereas the counts of clostridia, including Clostridium perfringens and Enterobacteriaceace decreased significantly (p < 0.05). The levels of fusobacteria and staphylococci were decreased significantly (p < 0.01) on day 7 of lactosucrose administration, while the counts of bacteroides increased significantly (p < 0.05) and day 14 of lactosucrose administration compared to pre-administration. In frequency of occurrence, bifidobacteria increased significantly (p < 0.001) during lactosucrose administration, while Spirochaetaceae and lecithinase-negative clostridia decreased significantly (p < 0.05) on day 14 of lactosucrose administration compared to pre-administration. No detectable change occurred in the counts of other organisms throughout the experimental periods. Fecal concentrations of ammonia, indole, ethylphenol, and urinary ammonia were reduced significantly (p < 0.05) on day 14 of lactosucrose administration. The water content and weight of the feces increased slightly during lactosucrose administration, but the pH values decreased slightly. The environmental ammonia and the fecal odor also decreased remarkably (p < 0.01) during administration.

Animals↗

Comparison of fecal Campylobacter in calves and cattle of different ages and areas in Japan.

To define the species of Campylobacter harboring in the intestine of calves and adult cattle and to examine their distribution among different age groups and farms, 34 calves and 60 adult cattle raised in 6 farms in 3 different areas were studied. Campylobacters were detected in the feces obtained from healthy calves (97.1%) less than 1-year-old but were much less frequently found in adult cattle (46.7%). Young calves harbored more species of Campylobacter than adult cattle. The isolation rate of campylobacters in adult cattle differed depending upon the farms examined. C. jejuni, C. hyointestinalis and C. fetus subsp. fetus were isolated from 61.8, 26.5, and 26.5% of calves, respectively. However, these 3 species were detected at the lower rates of 11.7 to 15.0% in adult cattle. C. coli, C. lari, C. fetus subsp. venerialis, C. fecalis, and other Campylobacter spp. were also detected in a few calves and adults. These results indicate that campylobacter colonization in the intestine is very common in young calves but not in adult cattle.

Aging↗

Effect of low-fat, high-fat, and fiber-supplemented high-fat diets on colon cancer risk factors in feces of healthy subjects.

Normal healthy volunteers (n = 8) received low- and high-fat (14% and 53% energy/day, respectively) and dietary fiber-supplemented high-fat diets (fiber 25 g/day, fat 52% energy/day) for 10 days each. Colon cancer risk factors in feces were measured by colonic nuclear aberration assay, the Ames Salmonella test using strain TA100, and measurement of bile acids and calcium soaps. Nuclear aberrations in colonic epithelium increased during the high-fat diet period and then decreased during the fiber-supplemented high-fat diet period. There were no significant differences in the mutagenicity on Salmonella TA100 or in the concentration of bile acids during the high-fat diet period. Bile acids decreased during the fiber supplementation period. The marked increase in calcium soaps during the high-fat diet period indicates an increase in long-chain fatty acids in the fecal lipid component and conversion of these fatty acids to insoluble calcium soaps when enough calcium is present.

Adult↗

Effect of left ventricular systolic pressure increase on ventricular arrhythmogenicity in old canine myocardial infarction.

OBJECTIVE: The aim was to examine the effect of an increase in left ventricular systolic pressure (LVSP) on ventricular arrhythmogenicity in old canine myocardial infarction. METHODS: Fourteen mongrel dogs of either sex weighing 11 to 15 kg were used. Studies were performed 28 d after creation of myocardial infarction by ligation of the anterior descending coronary artery. Electrical induction of ventricular arrhythmia and determinations of effective refractory period (ERP) and local intraventricular conduction delay (LIVCD) were performed using the extrastimulus technique with a cycle length of 300 ms in the normal and infarcted zones of the left ventricle. Heterogeneity of ERP (delta ERP) was determined as a difference between the longest and shortest ERP values in each site. LVSP was raised by constriction of the ascending aorta in a stepwise fashion (control, level A, level B). RESULTS: Incidence of electrically induced ventricular arrhythmia was increased from 28.6% at control level of LVSP [130.7(SEM 7.3) mm Hg] to 42.9% at level A [190.9(6.0) mm Hg] and to 64.3% (p < 0.05) at level B [243.3(4.0) mm Hg]. delta ERP and LIVCD were greater in the infarct zone than in the normal zone at each level of LVSP (p < 0.001). delta ERP in the infarct zone increased from 18.9(4.3) ms at control level of LVSP to 20.7(6.8) ms at level A, and to 27.1(8.1) ms at level B (p < 0.001). LIVCD in the infarct zone also increased from 22.9(6.2) ms at control level of LVSP to 26.8(4.9) ms at level A (p < 0.001), and to 36.1(6.0) ms at level B (p < 0.001). delta ERP and LIVCD in the normal zone were only slightly raised by increasing the LVSP. delta ERP and LIVCD in the infarct zone were closely correlated with incidence of electrically induced ventricular arrhythmia. CONCLUSIONS: Increasing the LVSP enhances ventricular arrhythmogenicity and pre-existing electrophysiologic abnormalities of the heart in the presence of old myocardial infarction. Thus a rise in LVSP from any cause in the old myocardial infarction can be a trigger of life threatening ventricular arrhythmias.

Animals↗

DNA relatedness among Erysipelothrix rhusiopathiae strains representing all twenty-three serovars and Erysipelothrix tonsillarum.

The levels of relatedness among strains of Erysipelothrix rhusiopathiae (serovars 1 through 23 and type N) were estimated by performing DNA-DNA hybridization experiments with the type strains of E. rhusiopathiae and Erysipelothrix tonsillarum, which are the two Erysipelothrix species that have been described. Two distinct DNA relatedness groups were identified. The group 1 strains, representing serovars 1, 2, 4 through 6, 8, 9, 11, 12, 15 through 17, 19, and 21 and type N, exhibited more than 73% hybridization with the type strain of E. rhusiopathiae but less than 24% hybridization with the type strain of E. tonsillarum. Group 2 included serovar 3, 7, 10, 14, 20, 22, and 23 strains, and these strains exhibited more than 66% hybridization with the type strain of E. tonsillarum but less than 27% hybridization with the type strain of E. rhusiopathiae. Strains representing serovars 13 and 18 exhibited low levels of hybridization (16 to 47%) with both of the type strains, indicating that these serovars may be members of a new genomic species. The members of the E. rhusiopathiae and E. tonsillarum groups resembled each other in many phenotypic characteristics, but differed in their ability to produce acid from saccharose and in their pathogenicity for swine. Our results confirm that the genus Erysipelothrix contains two main genomic species, E. rhusiopathiae and E. tonsillarum, which can be differentiated into serovars.

Animals↗

Taxonomic study of the Lactobacillus acidophilus group, with recognition of Lactobacillus gallinarum sp. nov. and Lactobacillus johnsonii sp. nov. and synonymy of Lactobacillus acidophilus group A3 (Johnson et al. 1980) with the type strain of Lactobacillus amylovorus (Nakamura 1981).

Biochemical properties and DNA-DNA reassociation studies of Lactobacillus acidophilus strains isolated from humans and animals indicate that these include six genomospecies. Two new species can be differentiated from the established species of the genus Lactobacillus: L. gallinarum sp. nov. (type strain, ATCC 33199) and L. johnsonii sp. nov. (type strain, ATCC 33200). Furthermore, it was clarified that L. acidophilus group A3 (Johnson et al. 1980) is synonymous with L. amylovorus.

DNA, Bacterial↗

Impact of Bifidobacterium longum on human fecal microflora.

The effects of Bifidobacterium longum feedings for five weeks on the fecal microflora, water contents, pH values, ammonia concentration, and beta-glucuronidase activity were investigated in five healthy human volunteers. Although numbers of major bacterial groups of the fecal microflora were not changed by the bifidobacteria feedings, a remarkably decreasing number of lecithinase-negative clostridia was observed. The percentage of lecithinase-negative clostridia and bacteroides to the total bacterial numbers isolated were decreased during the feedings and numbers of C. paraputrificum and C. innocuum were reduced. A significant reduction of fecal pH values for the last week of the feeding was observed. Ammonia concentration and beta-glucuronidase activity in the feces during the feedings were significantly lower than those before or after the feedings. The oral supplement of B. longum may be introduced to improve the fecal properties such as fecal ammonia concentration and beta-glucuronidase activity, but not the composition of fecal flora.

Administration, Oral↗

Effect of bilateral stellectomy on electrical instability of the atrium in the dog with hypokalemia.

To investigate the effect of sympathetic nerve activity on electrical instability of the atrium in the presence of hypokalemia, open chest electrophysiological study was performed before and after bilateral stellectomy (BS) in 15 dogs with hypokalemia (hypokalemia group) and in 15 dogs with normokalemia (control group). Hypokalemia was created by infusion of 5.0 g/kg of polystyrene sulfonic acid calcium into the colon. Serum level of potassium was significantly lower in the hypokalemia group (2.94 +/- 0.52 mEq/L) than in the control group (4.86 +/- 0.51 mEq/L, P less than 0.01) before BS. There was no significant change in serum level of potassium in the two groups after BS. Incidence of electrically induced atrial fibrillation (AF) was significantly higher in the hypokalemia group (80%) than in the control group (13%, P less than 0.001) before BS. It was significantly reduced in the hypokalemia group (40%, P less than 0.05), but not in the control group (6%) after BS. Dispersion of effective refractory period of the atrium (delta ERP) was significantly greater in the hypokalemia group (26.1 +/- 2.8 msec) than in the control group (22.0 +/- 3.3 msec, P less than 0.005) before BS. It was significantly decreased to 23.1 +/- 3.2 msec in the hypokalemia group (P less than 0.001) and to 20.6 +/- 2.5 msec in the control group (P less than 0.01) after BS. Maximum conduction delay in the atrium (MaxCD) was 36.1 +/- 3.5 msec before and 36.2 +/- 4.1 msec after BS in the hypokalemia group and 31.1 +/- 4.2 msec before and 32.3 +/- 4.9 msec after BS in the control group. There was a significant difference in MaxCD between the two groups before BS. Atrial fibrillation threshold (AFT) was significantly lower in the hypokalemia group (3.9 +/- 0.7 mA) than in the control group (13.8 +/- 3.1 mA, P less than 0.001) before BS. It was significantly increased both in the hypokalemia group (6.5 +/- 1.3 mA, P less than 0.001) and in the control group (15.0 +/- 2.7 mA, P less than 0.005) after BS. It is concluded that sympathetic nerve activity may play some role in the increase in electrical instability of the atrium in the presence of hypokalemia.

Animals↗