Biomedical subjects
Publications and source records attributed to T Mitsuoka.
A selective agar plate medium (tannin-treated brain heart infusion agar supplemented with colistin-oxolinic acid) was developed to enumerate tannin-protein complex-degrading Streptococcus bovis in the feces of koalas. This medium was successfully used to enumerate strains from fecal samples but failed to enumerate those from pure cultures.
A thirty-five-year-old woman without organic heart disease who has exercise-induced ventricular arrhythmias suppressed by propranolol and diltiazem is reported. Treadmill exercise provoked reproducibly nonsustained ventricular tachycardia (NSVT) and salvos of ventricular premature contraction (VPC). QRS morphology of these ventricular arrhythmias showed left bundle branch block pattern and right axis deviation. Oral propranolol (20 mg) and diltiazem (90 mg) prevented exercise provocation of NSVT and VPC. However, oral mexiletine (200 mg) and procainamide (500 mg) could not prevent exercise provocation of these ventricular arrhythmias. No ventricular arrhythmias could be induced by any form of ventricular extrastimulations. Right ventricular pacing at a rate of 210 beats/minute provoked NSVT of which the QRS morphology was similar to that of exercise-induced NSVT. Triggered activity may be a possible electrophysiologic mechanism for exercise-induced ventricular arrhythmias in this patient, although other mechanisms such as reentry and enhanced automaticity could not be completely excluded.
Microbial reduction of 1-phenyl-2-nitro-1-propene (3) was carried out using 57 strains of yeast, 40 strains of aerobic and facultatively anaerobic bacteria and 40 strains of strictly anaerobic bacteria. Nine strains of yeast (Candida tropicalis, etc.,) had the ability to reduce (3) to 1-phenyl-2-nitropropane (1) (94.1%-60.3% yield). The ability of the aerobic and anaerobic bacteria was weaker than yeast (35.6%-14.0% and less than 5%, respectively). When 11 strains of strictly anaerobic bacteria (Clostridium innocuum etc.,) were used, a final reduced product like amphetamine (2) was detected, although the efficiency of reduction was very poor.
Spontaneous glomerular lipidosis was found in a 12-week-old male Syrian hamster of the APA strain. Lipids in the glomeruli were observed as droplets in a prominently expanded mesangial area and as emboli in a dilated capillary lumen. Lipid deposition was also, but less often, detected in tubular epithelial cells and interstitial cells around the lipid-laden glomeruli. This case of glomerular lipidosis was considered to be closely related to hyperglycaemia and hyperlipidaemia.
To assess the relative contribution of sympathetic and vagal influences on diurnal variation of sinus node recovery time (SNRT) in sick sinus syndrome (SSS), the diurnal changes of SNRT and the effects of propranolol and subsequent atropine on SNRT were examined in 39 patients with SSS. SNRT was measured before and after intravenous propranolol (0.1 mg/kg), and after subsequent intravenous atropine (0.02 mg/kg) in the cardiac catheterization laboratory. After completion of the electrophysiologic studies in the laboratory, SNRT was measured at 0 a.m. (midnight), 6 a.m. and 12 noon on the following day in the ward. After propranolol, SNRT was prolonged in 22 of 26 patients and shortened in 4 patients. After subsequent atropine, SNRT was prolonged in 5 of 26 patients and shortened in 21 patients. The patients with SNRT longer than 3 sec had a tendency to have greater diurnal variation of SNRT than those with SNRT less than 3 sec. A strong correlation (r = 0.98) was found between SNRT after propranolol and the longest SNRT in a 24-hour period. A difference of SNRT between after propranolol and after subsequent atropine was significantly correlated (r = 0.88) with a difference between the longest and the shortest SNRT in a 24-hour period. These results suggest that the diurnal changes in SNRT are regulated by the autonomic nervous system in SSS. SNRT after propranolol may be useful in estimating the longest SNRT in a day.
Specific pathogen free BALB/c mice from 3 commercial laboratory animal breeders in Japan were compared on the composition of caecal flora revealed by selective and nonselective cultivation as well as direct microscopical observation on smears, and relative caecal weight. Large differences were detected in viable counts of total bacteria and almost all bacterial groups, while direct microscopical counts which consisted mainly of fusiform bacteria were almost equal, resulting in diverse recovery rates among 3 breeders. Eubacterium and spiral shaped organisms were not detected from all breeders. There also existed variations within breeders, especially those in the number of Enterobacteriaceae. Relative caecal weight also differed among breeders, suggesting the participation of variety of caecal bacteria in determining this parameter. As these variations in bacteriological status of animals can influence experimental results, standardization of intestinal microbial flora is required.
The bile duct system of normal rats was examined histochemically. Although the apical surface of biliary and glandular epithelial cells was positively stained with Concanavalia ensiformis (Con A), Dolichos biflorus (DBA), Glycine max (SBA), Ulex europeus-I (UEA-I) and Triticumvulgaris (WGA), the cytoplasm did not apparently react with any lectins. Therefore these cells might not play an important role in an active secretion of mucin. On the other hand, the cytoplasm of goblet cells was positively stained with periodic acid-Schiff, high iron diamine, Con A, DBA, Griffonia simplicifolia-II (GS-II), SBA, UEA-I, and WGA. This suggests that mucin secreted from the goblet cells may be acid one with sulfonic terminals.
1. Microbial reduction of 1-phenyl-2-nitropropane 1 was carried out using 40 strains of intestinal anaerobic bacteria. Among them, 12 strains (Mitsuokella multiacidus, Clostridium perfringens, C. innocuum, C. clostiriiforme, C. difficile, C. butyricum, C. sp., Eubacterium limosum, E. aerofaciens, E. multiforme, Peptostreptococcus anaerobius and P. productus) had the ability to reduce 1 to amphetamine 2 (0.1-1% yield). 2. Clostridium species were more active than another intestinal anaerobic bacteria. 3. When Clostridium perfringens was used in preparative fermentation, the yield of 2 was increased, and its absolute structure had an (S)-configuration with an optical purity of 68% in enantiomeric excess.
Effects of cyclophosphamide (CY) on the antibody titer level and incidence and severity of swine serum (SS)-induced bile duct lesion (BDL) were examined. BDL induced by 0.2 ml of SS per head twice a week for 2 weeks was characterized by hyperplasia of biliary epithelial cells, proliferation of mucous glands, and periductal infiltration of eosinophils with mild fibrosis. CY showed no significant influence on the above-mentioned parameters at the dose levels of 140 and 210 mg/kg. On the other hand, CY lowered the antibody titer level and decreased the severity of BDL at the dose level of 280 mg/kg, and it suppressed the antibody response and BDL at the dose level of 280 x 2 mg/kg. Thus the antibody titer level and the severity of BDL were closely related each other.
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The effect of hypercalcemia on T wave morphology, polarity, and amplitude was studied in 14 patients with a primary diagnosis of malignant lymphoma (8 patients), adult T-cell leukemia (5 patients), and Hodgkin's disease (1 patient). Hypercalcemia was severe to extreme in 11 (14.9-22.8 mg/dl), moderate in 1 (13.4 mg/dl), and mild in 2 (11.8 and 12.2 mg/dl) patients. Ten of the 11 patients (91%) with severe hypercalcemia showed inverted, biphasic, and notched T waves, mainly in the chest leads. Notched T waves were observed in all 10 of these patients in anterior to lateral, mid to lateral, or lateral chest leads. Biphasic and/or inverted T waves in anterior or anterior to midchest leads were present in 4 of these 10 patients who had extreme hypercalcemia (greater than 16 mg/dl). Changes in T wave morphology were not observed in moderate or mild hypercalcemia. T wave amplitude showed significant inverse correlation with serum calcium (T mV vs Ca, r = -0.60, p less than 0.001; T/R ratio vs Ca, r = -0.68, p less than 0.001; n = 35). Decrease in T wave amplitude was marked in severe hypercalcemia (p less than 0.0001) and moderate hypercalcemia, but there was no change in mild hypercalcemia. Changes in T wave morphology, polarity, and amplitude either appeared with development of hypercalcemia or disappeared with normalization of serum calcium level. It was concluded that in addition to shortening the QT interval, severe to extreme hypercalcemia can cause development of inverted, biphasic, or notched T wave with a marked decrease in amplitude of T waves.
The growth characteristics of Tyzzer's organisms in cultured mouse hepatocytes were examined by direct bacterial counting and plaque assay. The viability of propagated bacteria and time required for the maximum titers depended on incubation time and inoculum dose, respectively. Both infectious titers and bacterial counts at optimum harvests were much higher than those obtained from infected mouse livers. Immunofluorescence revealed, after a lag phase of about 2 h, a linear multiplication during a 6 h period.
Comparative studies of physiology, biochemical characteristics, and morphology by electron microscopy were conducted on Bifidobacterium pseudolongum SS-24 isolated from dogs and Bifidobacterium thermophilum SS-19 isolated from swine. Both B. pseudolongum and B. thermophilum grow unusually rapidly in the rumen fluid medium of Scott and Dehority, and reached a maximum of optical density after only 6 to 7 h of incubation. B. pseudolongum and B. thermophilum showed similar patterns of results for 21 biochemical characteristics tested, with a difference found only for N-acetyl-glucosaminidase. Scanning electron micrographs revealed that B. pseudolongum produced extensive amounts of extracellular material. The cell walls of B. pseudolongum and B. thermophilum were totally different. Transmission electron micrographs of ruthenium red-stained preparations of B. pseudolongum showed a very thick (ca. 0.2 microns) Gram-positive cell wall, whereas B. thermophilum was found to have a thin (ca. 0.05 microns) Gram-positive cell wall.
Factors affecting the infectivity of Tyzzer's organism, an obligate intracellular bacterium, were examined in cultured mouse hepatocytes. The organisms were subjected to physical and chemical impairments and the infectivity was estimated by immunofluorescence that discriminated adhesion and entry of the organisms to host cells and by the plaque assay. Pretreatment of the organisms with either mild heat or formalin abolished adhesion. UV irradiation completely removed the plaque forming ability, while adhering and entering capacity were more resistant in this order. Entry of the organism into host cells was suppressed in the presence of erythromycin, gentamicin or oxytetracycline, while it was relatively little susceptible to ampicillin, kanamycin or rifampicin. Plaquing efficiencies were increased by centrifugation during the infection. These results suggest that not only a structural but also a functional integrity of the organisms was requisite for establishment of the infection at the initial stage.
The initial phase of infection with Tyzzer's organisms in cultured mouse hepatocytes was observed using indirect immunofluorescence (IF) and a plaque assay. The organisms adhered poorly to aldehyde- or acetone-fixed cells, but once adhered to host cells, whether methanol-fixed or unfixed, they were not removed by methanol or acetone. By the IF as well as the plaque assay, both of which discriminated intra- and extracellularly located organisms, the number of cell-associated organisms increased linearly up to 3 h post-inoculation. The number of intra-cellular organisms increased rapidly in the first 1 h, followed by linear increase at a much lower rate. Similar results were obtained by the plaque assay.
The effects of brown rice, containing fourfold as much dietary fiber as polished rice, on the human fecal microflora were determined. Significantly increased numbers of Bifidobacterium adolescentis and Enterococcus faecalis were observed during the brown rice intake, whereas the total counts and the numbers of bacteroides, Eubacterium aerofaciens, and Escherichia coli during the intake were lower than those before and after the intake. Lower numbers of clostridia and low incidences of Clostridium paraputrificum and C. perfringens were observed during the brown rice intake.
The faecal floras of two adult (male and female) and one infant (male) giant panda kept at the Ueno Zoo, Tokyo, Japan were examined and shown to be quite different from those of other animals. The predominant bacteria in the adults were Streptococcus (including Enterococcus) and Enterobacteriaceae, while obligate anaerobes had minor populations. Fastidious anaerobes were not detected. The predominant bacteria in the suckling infant were Lactobacillus and Streptococcus, followed by Bifidobacterium. After the infant began to eat bamboo leaves the number of Lactobacillus decreased and Bifidobacterium became undetectable, whereas Enterobacteriaceae became one of the most predominant flora. The most dominant streptococcus isolated from the female panda was identified as Streptococcus bovis, but those from the male adult and the weaned infant were not identified as any known species.
The Fecal microflora of 15 healthy elderly persons with a median age of 84 years in a rural area whose inhabitants tend to be long-lived (Yuzurihara-area, Uenohara, Yamanashi Prefecture) was compared with the microflora of individuals with a median age of 68 years in an urban area (Tokyo). The diet of the elderly persons in the Yuzurihara area is characterized by a high intake of dietary fiber. Total numbers of anaerobic bacteria were significantly smaller in the elderly persons in the Yuzurihara area than those in the Tokyo area. A significantly large number of bifidobacteria, but not of lecithinase-negative clostridia, was observed in the elderly persons in the Yuzurihara area. Large numbers and high incidences of bacilli and lecithinase-positive clostridia (mainly Clostridium perfringens) were found in the elderly persons in the Tokyo area. Twenty-five genera and over 81 species were isolated from the elderly persons in the Yuzurihara area, and 25 genera and over 92 species were isolated from the elderly persons in the Tokyo area. Furthermore, significantly larger numbers of Bifidobacterium adolescentis and Fusobacterium mortiferum strains were found in the Yuzurihara group, but significant reductions in the Bacteroides buccae-oris group, B. thetaiotaomicron, Bacteroides spp., C. coccoides, C. paraputrificum, and Clostridium spp. were observed in the same group. A significantly higher isolation rate of Bacillus subtilis was observed in the elderly persons in the Tokyo area. The difference in the fecal microflora between elderly persons in Yuzurihara and those in the Tokyo area might be due to a difference in the intake of dietary fiber.