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Biomedical subjects

K Ameno

Publications and source records attributed to K Ameno.

At least 55 records · Page 3Linked to original sources
PubMed1994

Different distribution of paraquat and diquat in human poisoning cases after ingestion of a combined herbicide.

This report describes a slight difference in the rate of decrease of serum paraquat and diquat concentrations in eight human cases of poisoning by the herbicide PreegloxL (containing paraquatCl2, 5% and diquatBr2, 7%) and the distribution of each in three autopsied cases. There was no variation between the serum concentrations of paraquat and diquat within 24 h after ingestion, but paraquat remained at a slightly higher concentration than diquat after more than 24 h. The decrease of urinary paraquat and diquat concentrations was almost the same during the 24-h determination period. In three autopsied cases, diquat concentrations in the tissues were relatively lower than those of paraquat, except in bile. Paraquat and diquat were unevenly distributed in various tissues and fluids, but the distribution patterns of each in any particular tissues were quite similar. As no difference was observed in the decrease of urinary paraquat and diquat, the much higher concentration of diquat in bile indicates that bile may be one of the effective factors in lowering the concentration of diquat in serum and in tissues of the human body long after ingestion.

Adult↗
PubMed1994

A study of urinary dolichols as a biological marker for alcohol abuse. Report 2: Comparison of urinary dolichols/creatinine concentrations among non-drinkers, moderate-drinkers and heavy-drinkers.

We report here the comparison of urinary dolichols/creatine (D/Cr) concentration ratios in male non-drinkers, moderate-drinkers and heavy drinkers at admission and during hospitalization, and also discuss its usefulness as a biological marker for alcohol abuse. Urine samples were collected from the following four experimental groups: non-(male and female) and moderate-drinker (male) volunteers, and alcoholic heavy-drinking patients (male) at admission for psychiatric treatment and after 9-15 days hospitalization (informed consent was obtained). Urinary dolichols were determined by high performance liquid chromatography after BondElutC18 (500 mg) extraction. Due to significant differences in urinary D/Cr concentrations between male and female groups in non-drinkers and because the heavy-drinkers available for this study were exclusively male, comparison of the value of urinary D/Cr concentration ratios was subsequently limited to male only. There were no statistical differences in urinary D/Cr concentrations in the male among non-drinkers, moderate-drinkers and heavy-drinkers at admission. The accuracy of urinary D/Cr as a biological marker for alcohol abuse, calculated using the mean +/- 2 s.d. in non- and moderate-drinkers as the normal range, is only 33.3% in heavy-drinkers at admission, while their value of gamma-GTP in serum was 88.3%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

A study of urinary dolichols as a biological marker for alcohol abuse. Report 1: Quantitation of urinary dolichols by high performance liquid chromatography after BondElutC18 (500 mg) cartridge extraction.

This report describes the quantitation of urinary dolichols (Dolichol-90, -95 and -100) by advanced high performance liquid chromatography (HPLC) after BondElutC18 (500 mg) cartridge column extraction. The urine sample (15 ml) mixed with heneicosaprenol as internal standard (IS, 300 ng) was adjusted to pH 3 by 0.1N hydrochloric acid (HCl). BondElutC18 (500 mg) column was preactivated by methanol (4 ml) and distilled water (4 ml), and the urine sample was applied. The column was washed by HCl-sodium acetate buffer (pH 3, 6 ml), distilled water (4 ml) and methanol (4 ml), and then eluted by 2-propanol/dichloromethane/methanol (5/3/2 by vol, 4 ml). After drying the eluted solution under nitrogen gas flow, the residue was dissolved in 60 microliters of HPLC mobile phase, and 20 microliters of the mixture was injected into the HPLC. The HPLC conditions were as follows: column, mu Bondapack C18 (Waters); mobile phase, 2-propanol/methanol (72/28 by vol), 1.0 ml/min; detection, UV at 210 nm. Recovery yields of Dolichol-90, -95 and -100 were in the range of 68-75% and the calibration curve of each dolichol was linear over the range 0.01-1.00 micrograms.

Alcoholism↗
PubMed1994

[Blood ethanol levels and the CTP2E1 C2 allele].

The effect of CYP2E1 upon the blood ethanol level was investigated. Blood ethanol concentrations in 2 volunteers whose ADH2, ADH3 and ALDH2 genotypes were identical, were determined after intravenous administrations of 0.15 g/kg of ethanol by gas chromatography. beta 60 (0.28 mg/ml/hr) of the blood ethanol concentration-time curve in one with the CYP2E1 C2 allele was higher than that (0.25 mg/ml/hr) in the other with no C2 allele. It is possible that the C2 allele may correspond to the higher CYP2E1 activity of ethanol metabolism.

Aldehyde Dehydrogenase↗
PubMed1993

[Experimental studies of postmortem diffusion of toluene in blood, brain, muscle and fat of rats exposed to toluene vapor].

This report describes the postmortem diffusion of toluene in blood, brain, muscle and fat of rats exposed to toluene vapor. After exposure to toluene vapor (4,000 ppm) for 15 and 60 min, rats were killed by CO2 exposure and left for 12 and 24 hours in a fresh air. Toluene concentrations in blood, brain, muscle and fat were determined by head space gas chromatography. Postmortem decrease of toluene concentration in blood and increase of that in fat were observed with postmortem interval in both exposure conditions. But an extremely larger postmortem changes in the short exposure than those in the long exposure were observed. These are due to the facts that the value of fat/blood toluene concentration ratio at the time of death in the short exposure (3.3) was extremely smaller than that in the long exposure (10.5). Postmortem increase in muscle was also observed slightly. Postmortem concentrations in brain in both exposure intervals were relatively constant during these experiments. This postmortem stability is attributable to its anatomical features. These results suggest that brain toluene concentration at the autopsy is useful for the estimation of blood toluene concentration at the time of death and by comparison between toluene concentration in blood and that in brain it may be possible to presume the circumstances of death.

Adipose Tissue↗
PubMed1993

[In vitro studies of the metabolism of paraquat and diquat using rat liver homogenates--isolation and identification of the metabolites of paraquat and diquat].

The metabolism of paraquat and diquat was studied in vitro using rat liver homogenates, and the resulting metabolites were identified. Rat liver was homogenized with three volumes of isotonic buffer, and aliquots of the homogenate were preheated in a boiling water bath for 5 min prior to use. One milliliter of a mixture including both paraquat and diquat in an isotonic buffer solution (10 micrograms ion/ml) was incubated with an equal volume of fresh or preheated homogenate for 1 to 60 min at 37 degrees C. Quantification of paraquat and diquat was carried out by high-performance liquid chromatography (HPLC). In the fresh homogenate, a gradual decrease of paraquat concentration (about a 30% decrease over 60 min of incubation) and a rapid decrease of diquat concentration (not detectable after 10 min of incubation) were observed, but the same phenomenon was not evident with the preheated homogenate. Analysis of the incubated mixture of fresh liver homogenate with paraquat and diquat revealed three unknown peaks on the HPLC chromatograms; these seemed to be breakdown products of paraquant and diquat. The products were isolated and purified from the mixture by Sep-Pak C18 cartridge extraction, HPLC, silica gel column chromatography and Sephadex LH-20 column chromatography. Analysis of the chemical structure of the purified compounds was performed by infrared spectroscopy, mass spectrometry and nuclear magnetic resonance spectroscopy. These analyses determined that paraquat-monopyridone (1',2'-dihydro-1,1'-dimethyl-2-oxo-4,4'-bipyridylium ion) was derived from paraquat, and that diquat-monopyridone (6,7-dihydro-4-oxodipyrido [1,2-a':2',1'-c] pyrazinium ion) and diquat-dipyridone (6,7-dihydrodipyrido [1,2-a:2',1'-c] pyrazine-4,9-dione) were derived from diquat. These results indicate that paraquat and diquat are metabolized by rat liver homogenate, diquat more readily so than paraquat. As the toxicity of these metabolites has been reported to be much lower than those of the parental compounds, it would seem that there is a system capable of detoxifying paraquat and diquat in rat liver.

Animals↗
PubMed1993

Hymenoptera sting anaphylaxis: detection and clinical significance of individual bee and wasp venoms specific IgE and IgG4 antibodies.

In Japan, an average of 37 fatalities per year related to bee or wasp stings were reported during the years 1979-1988. To confirm fatal anaphylaxis serologically, we measured bee or wasp venom specific IgE (sIgE) and IgG4 (sIgG4) antibodies in the sera of 22 patients who visited hospitals with either allergic or anaphylactic reactions after bee or wasp stings by using Enzyme-Linked Immunosorbent Assay. Specific IgE or IgG4 antibodies against Polistes apachus (Paper wasp) and/or a mixture of Polistes annularis, P. exceramans, P. fuscatus, and P. metricus venoms of Polistes genus were detected in 11 patients and the detection frequencies were the highest among positive antibodies against bee or wasp venoms. The severity of allergic reactions was graded from 0-4 according to Mueller. The detection frequencies of sIgE in Mueller grade 0-3 patients were in the range of 33% to 67%, and in grade 4 were 100%. Whereas, the detection frequency of sIgG4 was high (67-100%) in grade 2-4 patients. Especially high levels of sIgE and sIgG4 were detected in patients experiencing the most severe clinical reactions. The detection of venom specific IgE and IgG4 antibodies appears to be useful when determining bee or wasp stings as the cause of fatalities.

Adult↗
PubMed1993

A comparative study of ethanol absorption in the canine jejunum after pretreatment with cyanamide or pyrazole.

This report describes the retardation of ethanol absorption from the intestinal tract and reduction of portal blood flow by high acetaldehyde concentrations in dogs using a jejunal segment with the vascular supply intact. The cyanamide-pretreatment group (CY), in which an extremely high acetaldehyde concentration developed, in comparison with the control and pyrazole-pretreated (PY) groups, showed a gradual increase of portal blood ethanol, a 25% reduction in the amount of absorbed ethanol, and an 85% smaller absorption rate constant value (Ka). These facts indicate that the presence of a high acetaldehyde concentration in the blood results in a reduction of ethanol absorption and retardation of ethanol reaching the systemic circulation. The rapid reduction of portal blood flow and the lower ethanol level in the portal vein observed in the CY group, in comparison with the other two groups, also indicate that the reduction of ethanol permeability through the absorption site to the blood is an important retarding factor induced by acetaldehyde.

Acetaldehyde↗
PubMed1992

Regional brain distribution of toluene in rats and in a human autopsy.

Toluene concentrations in 9 brain regions of acutely exposed rats and that in 11 brain regions of a human case who inhaled toluene prior to death are described. After exposure to toluene by inhalation (2000 or 10,000 ppm) for 0.5 h or by oral dosing (400 mg/kg), rats were killed by decapitation 0.5 and 4 h after onset of inhalation and 2 and 10 h after oral ingestion. After each experimental condition the highest range of brain region/blood toluene concentration ratio (BBCR) was in the brain stem regions (2.85-3.22) such as the pons and medulla oblongata, the middle range (1.77-2.12) in the midbrain, thalamus, caudate-putamen, hypothalamus and cerebellum, and the lowest range (1.22-1.64) in the hippocampus and cerebral cortex. These distribution patterns were quite constant. Toluene concentration in various brain regions were unevenly distributed and directly related blood levels. In a human case who had inhaled toluene vapor, the distribution among brain regions was relatively similar to that in rats, the highest concentration ratios being in the corpus callosum (BBCR: 2.66) and the lowest in the hippocampus (BBCR: 1.47).

Adult↗
PubMed1992

Effect of acetaldehyde on ethanol absorption in the canine jejunum.

The effects of acetaldehyde on ethanol absorption from the intestinal tract were studied using canine jejunal segment. A thirty-centimeter jejunal segment with intact vascular supply was isolated, and jejunal absorption studies were performed by administering a 17% ethanol solution (0.4 g/kg) into the lumen of the jejunal segment. In the control group, blood ethanol concentrations in the portal vein increased rapidly, with a peak level of 9.8 +/- 1.9 mM 30 min after administration. In the cyanamide-pretreated group, dogs were injected intravenously with cyanamide (100 mg/kg), an inhibitor of acetaldehyde dehydrogenase, 150 min before ethanol dosing. The blood ethanol concentration in the portal vein of this group, accompanied by a high acetaldehyde concentration, increased gradually, reaching a peak of 10.7 +/- 1.84 mM 120 min after ethanol administration. Each concentration gradient corresponded to the systemic circulatory order from the portal vein for ethanol concentration, and from the hepatic vein for acetaldehyde concentration. The absorbed amount of ethanol in the control and cyanamide-pretreated groups was 94.9 +/- 4.1% and 69.3 +/- 4.8%, respectively. Pharmacokinetic analysis indicated that a presence of high acetaldehyde concentration in the blood resulted in less ethanol reaching the systemic circulation (control: 7.34 +/- 2.95 h-1, cyanamide-pretreated: 1.08 +/- 0.75 h-1). The results also suggest that the absorption of ethanol from the intestine decreases when there is a high acetaldehyde concentration in the blood.

Acetaldehyde↗
PubMed1992

[Studies on ethanol absorption from the intestine--blood ethanol and acetaldehyde concentrations in the various vessels].

We describe the concentration gradient of ethanol at different blood sampling sites of dogs dosed via the jejunal segment or intravenously, and the subsequent recovery of intestinal fluid from the jejunal segment. After laparotomy a 30 cm length of jejunal segment with intact vascular supply was isolated. Blood samples were collected from the portal vein, hepatic vein, aorta and inferior vena cava. A 17% ethanol solution was used for a small dose group (0.4 g/kg) and a 33% solution for a large dose group (0.8 g/kg). In the small dose and large dose groups administered the solution via the jejunal segment, ethanol concentration in the blood of the portal vein increased rapidly and the highest ethanol concentration was detected in the portal vein, followed, in descending order by the hepatic vein, aorta and inferior vena cava. The highest acetaldehyde concentration in blood was detected in the hepatic vein, followed by that in the aorta while the lowest was in the portal vein and inferior vena cava in both groups. Each concentration gradient corresponded in order to systemic circulatory order from the intestine (ethanol absorption site) for ethanol concentration, or from the liver (acetaldehyde formation area) for acetaldehyde concentration. There was no difference in ethanol concentration among the four sampling sites in the case of intravenous ethanol injection, but a gradation of acetaldehyde concentration similar to that in the jejunal segment dosed cases was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetaldehyde↗
PubMed1990

IgG subclass distributions of anti-horse serum antibodies and natural venom-antibodies produced in response to antivenom injection or snake bite in humans.

The Japanese Mamushi (Agkistrodon halys blomhoffi, BOIE) is the most common snake in Japan. Bite victims treated with antivenom (horse serum) can produce antibodies against the horse serum and the snake venom. We studied distributions of the IgG subclasses of both these antibodies produced in response to antivenom injection and snake bite. We found that IgG1 and IgG4 of each antibody in the victims' serum were present for a long period of time.

Animals↗
PubMed1990

[The distribution of toluene in the brain and its effects on the brain catecholamines in acute toluene poisoning].

The regional distribution of toluene in the brain and its effects on the brain catecholamine levels in rats is reported. Separate sets of rats were exposed to the toluene via inhalation, at 1,500 ppm and at 10,000 ppm respectively, and via an ingestion (400 mg/kg). Given these three exposure conditions, the values of brain/blood toluene ratios were found to be the highest in the brain stem areas (2.85-3.22) such as the pons and medulla oblongata, in the middle range in the midbrain, the thalamus, the caudate-putamen, the hypothalamus and the cerebellum (1.77-2.12), and in the lowest ranges in the olfactory bulb, the hippocampus and the cerebral cortex (1.22-1.64). The values of the partition coefficient of toluene in the brain regions and in the blood of rats examined in vitro were also the highest in the brain stem and the lowest in the cerebral cortex. The highest values of brain/blood toluene and partition coefficients of toluene in the brain regions and blood were obtained in the lipid-rich regions. These results suggest that toluene, which has a high lipid solubility and no protein binding capability, distributes according to lipid contents of the brain. The inhalation of toluene (1,500 ppm and 10,000 ppm) caused decreases in the noradrenaline (NA) levels in the dorsal part of rat pons, rich in locus coeruleus, and in the dopamine (DA) levels in the hypothalamus and ventral part of the rat midbrain, rich in substantia nigra.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1989

A fatal case of oral ingestion of toluene.

A 51-year-old male ingested orally a large quantity of toluene and died about 30 min later. The presence of toluene in body fluids and tissues was confirmed by gas chromatography and gas chromatography/mass spectrometry. Tissue distribution of toluene showed that the liver detected the highest content of toluene (433.5 micrograms/g), except for the stomach contents, followed by pancreas (88.2 micrograms/g), brain (85.3 micrograms/g), heart (62.6 micrograms/g), blood (27.6 micrograms/g), fat (12.2 micrograms/g) and finally cerebrospinal fluid (11.1 micrograms/g).

Chromatography, Gas↗
PubMed1989

Analysis of body sway pattern after alcohol ingestion in human subjects.

Movements of the centre of gravity during 60 s of standing with eyes closed and eyes open were analysed before and after alcohol ingestion up to 8 h in 37 healthy human subjects. Blood alcohol and acetaldehyde concentrations (BAC and BAcHC) were measured simultaneously. Among the parameters analysed, area of posturogram was the most sensitive indicator; it increased to 3.8 times that of the control value at 60 min, after 3.5 ml/kg of ingested whisky (mean BAC of this group was 1.4 mg/ml), with the eyes open. The Romberg ratio, which denotes eyes closed relative to eyes open, remained constant. By contrast, there was little change in stabilometry in cases of 1.2 ml/kg of whisky ingestion (mean BAC at 60 min was 0.58 mg/ml). It is considered that body sway starts to increase when the BAC level exceeds 0.6 mg/ml on average; this value is only higher than the threshold of positional alcohol nystagmus. Correlation coefficients between BAC and each parameter of the stabilogram in the eyes open condition, such as area, X- and Y-axis diameters, and velocity of body sway, were 0.53, 0.45 and 0.48, respectively (p less than 0.01). There was no positive correlation between BAcHC and these parameters.

Acetaldehyde↗