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Biomedical subjects

K Fujimoto

Publications and source records attributed to K Fujimoto.

At least 901 records · Page 50Linked to original sources
PubMed1981

[Variability in the effects of psychotic drugs on conditioned avoidance reactions in rats due to warning stimuli].

Different effects of methamphetamine (0.25-1 mg/kg, sc), chlorpromazine (0.5-2 mg/kg, sc), haloperidol (0.25-0.1 mg/kg, sc), diazepam (1-4 mg/kg, sc) and pentobarbital (5-20 mg/kg, sc) on Sidman avoidance response were investigated according to absence or presence of stimulus control. Thirteen adult male rats of Wistar strain were divided into two groups of 6 and 7 each, and trained under Sidman avoidance schedule (WS-group) and the same schedule associated with a 5 sec warning stimulus presentation (buzzer and light) (WS+group). There was no difference in the effect of methamphetamine between the two groups. The avoidance response was inhibited in dose-dependent manner regardless of the stimulus control after chlorpromazine and haloperidol. However, more marked inhibition was always observed in WS-group than in WS+group. Diazepam and pentobarbital also inhibited the avoidance response in WS-group when ataxia-producing doses were given, while no significant inhibition was observed after the same doses of the drugs in WS+group. Thus, the avoidance response without stimulus control was more susceptible to the drugs than that with stimulus control. The present results suggest that Sidman avoidance response is reliable to evaluate psychotropic drugs in screening test.

Animals↗
PubMed1980

A novel method of isolation and some characteristic properties of human pancreatic elastases.

One component of elastases of human pancreatic juice and pancreatic extract was obtained in a highly purified state by chromatography on a column of sawdust. The elastase obtained after repeated adsorption chromatography with NaCl-containing buffers was almost homogeneous by gel filtration and polyacrylamide gel electrophoresis. This elastase showed relatively high elastolytic activity, but relatively low hydrolytic activity towards succinyl trialanine p-nitroanilide, as compared with another component of pancreatic juice elastase (which was not absorbed onto sawdust). Both elastases isolated were alkaline earth metal-dependent enzymes.

Cations, Divalent↗
PubMed1980

A new one-step method for the cytochemical localization of ouabain-sensitive, potassium-dependent p-nitrophenylphosphatase activity.

A new one-step method for the light and electron microscopic localization of the ouabain-sensitive, K-dependent p-nitrophenylphosphatase (K-NPPase) activity of the Na-K-ATPase complex is introduced. The incubation medium contains p-nitrophenylphosphate (NPP) as substrate, lead citrate as the capture reagent, and dimethylsulfoxide (DMSO) as an activator. It is usable at the optimal pH of the K-NPPase, which is about pH 9.0 in the presence of 25% of DMSO. The effects of fixation, lead concentration, and DMSO on the enzyme activity were studied using rat kidney as a test tissue. The fixation of tissues in a mixture of 2% paraformaldehyde and 0.5% glutaraldehyde for 60 min at 0 degrees--4 degrees C preserved 45% of the enzyme activity. In the absence of DMSO, lead citrate (4.0 mM) caused 82% inhibition of the enzyme activity in fixed tissue. However, the addition of DMSO (25%) caused about 3-fold activation of the remaining activity. Cytochemical demonstration of the ouabain-sensitive K-NPPase activity was successfully made by this method at both light and electron microscopic levels.

4-Nitrophenylphosphatase↗
PubMed1980

Revaluation of the vectorcardiographic criteria in cases of myocardial infarction: a comparative study of the vectorcardiogram, the left ventriculogram and the scintigram.

The results of vectorcardiograms were compared with those of the left ventriculograms and scintigrams with thallium-201 in cases of myocardial infarction to confirm the vectorcardiographic criteria of the present authors. The percentage of agreement between the VCG and scintigram was 82.5% and higher than the percentage of agreement between the VCG and the left ventriculogram. The percentage of disagreement between the negative finding in the VCG and the positive finding in the scintigram was 5.1% and consequently, a close relation was found between the VCG and scintigram. However, as the possibility of infarction was high in cases in which the scintigram finding was positive, the vectorcardiographic criteria in cases in which the VCG findings were negative were rechecked and partially corrected. Consequently the percentage of negative findings were decreased to 3.2%. Our next step was to perform the following prospective study which confirmed that the disagreement found in the corrected criteria (1.0%) was in fact less than what had been observed in the initial criteria (5.0%). Accordingly, it can be concluded that the corrected vectorcardiographic criteria in myocardial infarction may be the more reliable and useful in determining the location of the infarcted area.

Heart↗
PubMed1980

Pigmented contact dermatitis from azo dyes. I. Cross-sensitivity in humans.

Eight patients suffering from pigmented contact dermatitis caused by the commerical Brilliant Lake Red R were patch tested with purified Sudan I and its several chemical analogues. Positive reactions were observed to Sudan I, Orange SS, Brilliant Lake Red R, Vacanceine Red, Yellow OB and Sudan II. Negative tests were obtained with Toluidine Red, Permanent Orange, Lithol Red and Sudan III. We found that the commerical Brilliant Lake Red R which has been said to be most important causative agent of pigmented contact dermatitis, contained Sudan I as a major impurity. The patients reacting to Brilliant Lake Red R always gave a positive reaction to Sudan I, but those reacting to Sudan I did not always give a positive reaction to Brilliant Lake Red R. This suggests that Sudan I is a potent sensitizer and may induce contact sensitivity and Brilliant Lake Red R itself is a weak sensitizer or a cross-reacting substance.

Adult↗
PubMed1980

Effect of autoxidized methyl linoleate on glutathione peroxidase.

To determine the effect of several oxidation stages of autoxidized methyl linoleate (AOML) on glutathione peroxidase (GSH-Px), several experiments were carried out. In the first experiment, GSH-Px was prepared from gastrointestinal tract and liver which were excised from mice, and the effects of AOML rich in hydroperoxides (HP) and that rich in the decomposition products of HP on the activity of GSH-Px were compared. The results indicate that GSH-Px indiscriminately metabolized both types of AOML without strict recognition of the specificity of the substrate. In the second experiment, it was noted that the inhibitory rate of GSH-Px by in vitro incubation with various AOML closely correlated with POV of the sample esters, but did not correspond with the toxicity revealed by intraperitoneal injection or intragastric feeding. In the next experiment, mice were given AOML with a low vitamin E diet for 45 days, and an increase of GSH-Px activity in gastrointestinal tract in proportion to the POV of the administered oil occurred, but the level in liver remained unchanged. On the contrary, the increase of GSH-Px activity by intraperitoneal injection of AOML in mice was marked in liver, but not in gastrointestinal tract. From these results, most of the orally administered AOML seemed to be reduced in the mucosa of the gastrointestinal tract. However, the marked increase of fluorescence in the lipid fraction of heart and kidney by oral administration of AOML suggested that the damage caused by it was not limited to gastrointestinal tract but was spread through the whole body.

Animals↗
PubMed1980

Quantitative analysis of cholesterol in foods by gas-liquid chromatography.

In order to develop a simple and exact analytical method for cholesterol determination in foods by gas-liquid chromatography, several experiments were carried out in collaboration with several universities and institutes. For the extraction of lipids from foods, it was decided that chloroform-methanol (2:1) extraction was the most suitable procedure. Since pretreatment procedures using methods such as thin-layer chromatography and florisil column chromatography to purify the unsaponifiable matters reduced the recovery of cholesterol, and good results were obtained without applying the pretreatment, these procedures were concluded to be unnecessary. Gas chromatograms obtained with free sterol showed results similar to those of the trimethylsilyl ether derivative and acetate. 5-alpha-Cholestane is used as a good internal standard.

Chloroform↗
PubMed1979

Isolation and characterization of mucopolysaccharides from rat liver mitochondria.

Mucopolysaccharides were isolated from rat liver mitochondria which had been labeled with 35S-sulfate. They were prepared from trichloroacetic acid (TCA)-insoluble and -soluble fractions of lipid-free mitochondria. These fractions were digested with pronase exhaustively, and the mucopolysaccharides were recovered in the void volume fractions of gel filtration of the pronase digests on Sephadex G-50, monitored by radioactivity determination. Identification of these mucopolysaccharides was based on electrophoresis on cellulose acetate film using three different media, enzymatic and chemical degradations specific to each type of mucopolysaccharide, using chondroitinases, heparitinase, and nitrous acid. From the TCA-insoluble fraction, chondroitin sulfate A and dermatan sulfate were obtained in a ratio of about 1 : 2, based on 35S-radioactivities, whereas the TCA-soluble fraction yielded chondroitin sulfates A/C, dermatan sulfate, and heparan sulfate in a ratio of about 1 : 3 : 12. The total amount of mitochondrial mucopolysaccharides was about 3 mg/g protein, distributed between the TCA-insoluble and -soluble fractions in a ratio of about 1 : 3.

Animals↗
PubMed1979

Brilliant Lake Red R as a cause of pigmented contact dermatitis.

Twenty-three patients suffering from pigmented contact dermatitis caused by cosmetics containing Brilliant Lake Red R were observed. Commercial samples of Brilliant Lake Red R proved to contain many ethyl acetate extractable impurities; 1-phenylazo-2-naphthol and azobenzene were isolated and identified. To determine the responsible allergens, five patients were examined by patch tests with purified samples of azo-dyes and the unidentified fractions of ethyl acetate extractable impurities. Three out of five showed weaker reactions to purified samples of Brilliant Lake Red R and the other two showed equal reactions compared to the commercial product. 1-Phenylazo-2-naphthol was found to be a strong allergen in all cases but none showed a positive reaction to azobenzene. Some unidentified fractions also gave positive results. Patch tests were performed with 4-phenylazo-1-naphthol, 4-phenylazo-1-naphthol-2-carboxylic acid, and 2,4-bis(phenylazo)-1-naphthol, as structurally related compounds derived from 1-naphthol. All gave negative and they were not detected in the ethyl acetate extractable impurities by thin-layer chromatography.

Adult↗