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Biomedical subjects

T Shibamoto

Publications and source records attributed to T Shibamoto.

At least 127 records · Page 7Linked to original sources
PubMed1988

A case of high altitude pulmonary edema followed by brain computerized tomography and electroencephalogram.

A case of high altitude pulmonary edema with high altitude cerebral edema was reported. A young Japanese male complained of severe palpitation and shortness of breath on the third day of climbing at 3,000 m above sea level. During the next 2 d at altitude, the following symptoms occurred: cough with foamy sputum, cyanosis, and loss of consciousness. Soon after evacuation, he showed severe hypoxemia and deep coma with decerebrate rigidity; electroencephalogram showed diffuse alpha waves, indicating "alpha wave coma." Brain computerized tomography revealed brain edema, showing small compressed ventricles and diffuse low density of the cerebrum. Pulmonary edema on chest roentgenogram disappeared by the fifth hospital day, and his consciousness recovered gradually during the next 2 weeks after the admission. He was examined serially by electroencephalography and brain computerized tomography. He recovered fully, but there were transient psychological abnormalities soon after discharge and mild brain atrophy was observed by brain computerized tomography 6 years later.

Adult↗
PubMed1988

[Primary carcinoma of the fallopian tube: its clinical aspects and problems in the postoperative staging system].

Clinical features of primary carcinoma of the fallopian tube were studied in 13 patients treated in Osaka National Hospital between 1961 and 1987. The relationship between clinical staging and prognosis in each patient is discussed. The incidence of this disease among all cases of malignant tumor in the gynecological department during the same 27-year period was 0.18%. The mean age of the patients was 50.7 years. Twelve patients (92%) were within the age range from 41 to 59 years, the most common age of onset. Six patients (46%) were nulligravida and 9 (69%) were nulliparous, suggesting infertility as a possible important risk factor for the disease. None of the six who underwent cervical cytodiagnosis showed tumor cells. Three were positive for cytodiagnosis by aspiration biopsy. The concomitant use of many drugs, including CDDP given postoperatively to 2 patients with advanced disease, was markedly effective. The radiotherapy carried out in 4 patients was ineffective. When the patients were staged according to the classifications of Dodson et al. and Schiller et al., there was no difference between these classifications in advanced cases. However, Dodson et al.'s classification was considered unsuitable for patients with early-stage cancerous lesions localized in the fallopian tube, while that of Schiller et al. was considered to be superior in evaluating prognosis.

Adult↗
PubMed1987

Biological and chemical studies on overheated brewed coffee.

Vapour formed from overheated decaffeinated coffee was condensed and tested for mutagenicity using the Ames assay in Salmonella typhimurium strains TA98 and TA100. Vapour produced at 73 and 100 degrees C exhibited no mutagenicity. The basic fraction of vapour produced at 350 degrees C showed weak mutagenicity towards strains TA98 with metabolic activation. The chemical analysis of this fraction identified pyridines and pyrazines as the major constituents. None of the compounds identified in this fraction has been reported as mutagenic when tested in the Ames assay.

Caffeine↗
PubMed1986

Salmonella/microsome mutagenicity tests of heat-processed milk samples.

Samples of whole milk were heat treated by commercial heat-sterilization, by commercial heat-pasteurization or by a laboratory heat-pasteurization (65 degrees C for 30 min). Each sample was tested for mutagenicity in Salmonella typhimurium strains TA98 and TA100 with and without S-9 mix. Dichloromethane extracts of milk heated at 100, 135 and 150 degrees C for 5 hr were also tested for mutagenicity using the same assay. None of these samples exhibited mutagenicity in the Ames assay used.

Animals↗
PubMed1986

Acute effect of paraquat on lung fluid balance and prostanoid production in awake sheep.

Paraquat, a widely used herbicide, causes severe lung damage in humans and laboratory animals. Pulmonary edema is a common initial feature of paraquat toxicity, but its pathophysiology is not well understood. The purpose of this investigation was to determine the acute toxic effect of paraquat (30 mg/kg) on pulmonary transvascular protein and fluid fluxes, histologic features, and prostanoid production, using awake sheep with chronic lung lymph fistulas (n = 6). Lung lymph flow increased significantly 3.5 h after intravenous infusion of paraquat and rose to 2.6 times baseline within 8 h (from 4.4 +/- 0.4 to 11.4 +/- 1.5 ml/h, p less than 0.05). Lymph-plasma protein concentration ratio increased during the same time period (from 0.64 +/- 0.05 to 0.75 +/- 0.04, p less than 0.05). Lung lymph protein clearance also increased at 3.5 h and remained elevated throughout the duration of the experiment. Pulmonary arterial and left atrial pressure were only slightly altered. Plasma and lung lymph thromboxane A2 (as TXB2) concentrations were significantly increased at 30 min and continued so thereafter. Plasma and lung lymph prostacyclin (6-keto-PGF1 alpha) concentrations increased significantly at 3 h and were more than 5 times baseline by 7 h. The time course of the increase in 6-keto-PGF1 alpha concentrations seemed similar to that of lung lymph flow. The high flow of protein-rich lymph strongly suggested an increase in pulmonary vascular permeability, which may indicate pulmonary endothelial damage. Histologic studies of the lungs revealed only minor changes in perivascular cuffing, minimal alveolar hemorrhage, and slight neutrophilic alveolar wall infiltration.(ABSTRACT TRUNCATED AT 250 WORDS)

6-Ketoprostaglandin F1 alpha↗
PubMed1986

[Studies on Campylobacter and Salmonella in feces of pregnant women and newborn infants].

Fecal cultures from five thousand four hundred and twenty-seven pregnant women, who were delivered at Osaka National Hospital from January 1, 1980 to December 31, 1984, were examined to detect intestinal Campylobacter and Salmonella during 30 and 36 gestational weeks. In addition, the feces of newborn infants were cultured three days after delivery to check for the presence of Campylobacter and Salmonella. During pregnancy, Campylobacter was detected in the feces of 116 women (2.14%), and Salmonella in 99 cases (1.82%). By administering antibiotics to the affected cases, the number of women whose fecal cultures were positive for Campylobacter and Salmonella at the time of delivery was reduced to 8 and 15, respectively. Neonatal fecal cultures revealed that Salmonella infection occurred in two among fifteen (13.33%) and Campylobacter infection in three among eleven (27.27%) infants whose mothers had been affected. These findings suggest the importance of adequate management for these bacterial infections during pregnancy and the perinatal period to prevent danger to the newborn.

Campylobacter fetus↗
PubMed1985

[The distribution of cefotaxime in serum, lung lymph and lung tissue of sheep].

The levels of cefotaxime (CTX) in serum and lung lymph were compared in awake sheep which were prepared for collection of lung lymph. A single dose of 50 mg/kg of CTX was administered intravenously to sheep. The CTX level in serum or lung lymph reached a peak within 15 minutes after administration and decreased rapidly. The measurable concentration persisted for 240 minutes after administration. Ratios of lung lymph to serum concentration of CTX ranged from 1.0 to 1.2. In addition, the CTX levels in serum, lung lymph and tissue of right lower lobe were compared in anesthetized sheep to which CTX 50 mg/kg were given. Ratios of lung lymph and tissue in right lower lobe to serum concentration of CTX were 0.81 +/- 0.14, 0.06 +/- 0.02, respectively. From above results, CTX was well distributed in lung lymph. The levels of CTX in tissue of right lower lobe were markedly lower than those of lung lymph.

Animals↗
PubMed1984

Mutagenicity of lichen constituents.

Usnic acid (the most abundant lichen constituents), physodic, and physodalic acids isolated from Hypogymnia enteromorph (Ach.) Nyl. were tested for mutagenicity in the Ames Salmonella/microsome assay. Physodalic acid exhibited clear dose-related mutagenicity against Salmonella typhimurium strain TA 100 with or without S9 mix in both plate-incorporation and preincubation assays. The addition of S9 mix increased the number of revertants approximately threefold and fourfold in preincubation and plate-incorporation assays, respectively.

Animals↗
PubMed1984

Mutagen formation in browning model systems.

A browning model system, consisting of diacetyl and ammonia, produced frameshift and base-pair substitution mutagens when the system was heated over 20 min and 120 min, respectively. The major product was 2,4,5- trimethylimidazole , which showed no mutagenicity toward Salmonella typhimurium strains TA98 and TA100 with or without metabolic activation. When furfural was reacted with nitrate under mild conditions (for 30 min to 3 h at 0-25 degrees C and pH 2-7), it did not produce mutagenic nitrofuran derivatives. However, the ethyl ether extract obtained from the reaction mixture of furfural and nitrate with hydrochloric acid exhibited strong mutagenic activities toward S. typhimurium strains TA98 and TA100 in the presence of metabolic activation. The major product of this reaction mixture, 4- nitrofurfural , exhibited no mutagenicity toward tester strains TA98 and TA100 with or without metabolic activation. Pure active mutagen(s) was (were) not, however, identified in either system.

Ammonia↗
PubMed1984

Mutagenicity of 2-hydroxyalkyl-N-nitrosothiazolidines.

The mutagenicity of 2-hydroxyalkyl-N- nitrosothiazolidines was tested using Salmonella typhimurium strains TA98 and TA100. The N- nitrosothiazolidines tested were unsubstituted N- nitrosothiazolidine (NT), N- nitrosothiazolidine -4-carboxylic acid ( NTC ), 2-hydroxymethyl-N- nitrosothiazolidine ( HMNT ), 2-(1,2,3,4- tetrahydroxybutyl )-N- nitrosothiazolidine , 2-(1,2,3,4- tetrahydroxypentyl )-N- nitrosothiazolidine , 2-(1,2,3,4,5- pentahydroxypentyl )-N- nitrosothiazolidine ( PHPNT ) and 2-(1,2,3,4,5- pentahydroxypentyl )-N- nitrosothiazolidine -4-car boxylic acid. Among the N- nitrosothiazolidines tested, only HMNT and PHPNT exhibited clear dose-response mutagenicity toward strain TA100 with or without metabolic activation. None of the 2-hydroxyalkyl-N- nitrosothiazolidines were mutagenic to strain TA98. NT exhibited much stronger mutagenicity than either HMNT or PHPNT . Mutagenic activities of NT and PHPNT were eliminated by carboxyl substitution in the position alpha to the N-nitroso group.

Animals↗
PubMed1984

Ames mutagenicity tests of products from a heated potato-starch system.

A charred sample was prepared from potato starch heated with ammonium carbonate at 600 degrees C in a flask under a nitrogen stream. The water produced was collected and extracted with methylene chloride. The basic fraction obtained from the extract exhibited strong mutagenicity in Ames assays using Salmonella typhimurium strains TA98 or TA100 with metabolic activation (rat-liver S-9 mix). The basic fraction was further fractionated by silica gel column chromatography and subsequently by Sephadex column chromatography. Some of the resulting fractions exhibited strong mutagenic activities in S. typhimurium strain TA98 with S-9 mix.

Carbonates↗
PubMed1984

Ames mutagenicity tests of overheated brewed coffee.

Five kinds of coffee samples were prepared from a commercial drip-grind coffee in order to examine the mutagenicity of brewed coffee using the Ames test. The samples prepared were a thick coffee syrup, coffee solid residues, dichloromethane and ethanol extracts of solid residues, a dichloromethane extract of a distillate from normally heated brewed coffee and dichloromethane extracts of distillates from overheated (150-300 degrees C) brewed coffee. The samples were tested for mutagenicity towards Salmonella typhimurium strains TA98 and TA100 both with and without metabolic activation (S-9 mix). Only the extracts of the distillates obtained from coffee heated to 150 degrees or 300 degrees C exhibited mutagenicity towards strain TA98 with S-9 mix.

Coffee↗
PubMed1984

Genotoxicity of N-nitrosothiazolidine in microbial and hepatocellular test systems.

The genotoxicity of N-nitrosothiazolidine was studied in a microbial system and in a hepatocellular system. The compound showed positive responses in both tests, exhibiting weak mutagenicity at the lowest level tested (1 mg/plate) in the rec assay in Bacillus subtilis, and inducing statistically significant levels of DNA repair in primary hepatocyte cultures at concentrations ranging from 2 X 10(-4) to 2 X 10(-3) M.

Animals↗
PubMed1984

Effects of elevated-hematocrit levels on pulmonary circulation in conscious sheep.

We investigated the effects of stepwise hematocrit (Ht) increase on pulmonary circulation in conscious sheep (n = 7). The Ht was increased by an isovolumic exchange transfusion of blood with centrifuged red cells. By increasing the Ht-values, both systemic (PSA) and pulmonary artery pressures (PPA) were increased, with the degree of PPA increment greater than that of PSA. Cardiac output (CO) was slightly decreased by increasing the Ht. Also, A-V difference values of blood oxygen tension were reduced with elevation of the Ht values. The ratio of the right ventricular work rate (RVW) to the left one (LVW), RVW/LVW, was shown to increase remarkably with increased Ht. This increase was considered to be supporting evidence for the right ventricular hypertrophy in high altitude acclimatization. A strong positive correlation was observed between Ht and blood viscosity. It was thus confirmed that Ht effect was greater in pulmonary circulation than in systemic circulation.

Altitude↗
PubMed1983

Possible mutagenic constituents in nitrite-treated soy sauce.

Soy sauce was heated with 100, 500, 1000 or 2000 ppm sodium nitrite for 30 min at 80 degrees C and pH 3. The reaction mixtures were extracted with dichloromethane followed by ethyl acetate. After removal of the solvents, the extracts were subjected to analysis (gas chromatograph-thermal energy analyser and gas chromatograph-mass spectrometer) and Ames mutagenicity tests. N-Nitrosodimethylamine and N-nitrosodiethylamine were found in the dichloromethane extract of the soy sauce treated with 2000 ppm nitrite at levels of 10 and 120 micrograms/ml, respectively. N-Nitrosoproline was identified in the ethyl acetate extract of the same sample at a level of 0.5 microgram/ml. Both extracts exhibited dose-related mutagenicity in Salmonella typhimurium strain TA100 with S-9 mix. The dichloromethane extract showed much higher mutagenicity than did the ethyl acetate extract. The samples obtained from soy sauce treated with 100, 500 and 1000 ppm nitrite were not mutagenic, but N-nitrosodiethylamine was detected by thermal energy analysis in the soy sauce treated with 1000 ppm nitrite. The addition of 10,000 ppm L-ascorbic acid, along with 2000 ppm nitrite, to soy sauce prevented the formation of mutagenic materials or detectable nitrosamines.

Animals↗