Effect of adenosine agonist (propentofylline) on rat hippocampal seizures induced by microdialysis with potassium: analysis using compressed EEG power spectrum array.
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Adenosine↗
Biomedical subjects
K Morimoto
Publications and source records attributed to K Morimoto.
Changes of the afterdischarge threshold in the primary and secondary sites during kindling of cats. I: A study in limbic kindling.
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Amygdala↗
The mechanism of human placental urea transport: a study using placental brush border (microvillous) membrane vesicles.
To elucidate the mechanism of placental amino acid transport, the transport of amino acids into brush border membrane vesicles was investigated using brush border membrane vesicles (BBMV) separated from the human full-term placenta. 1. The transport of l-alanine and l-glutamine into the brush border membrane vesicles prepared from either early gestational placenta or full-termed placenta disclosed a typical overshooting phenomenon in the presence of H+ concentration gradient (extravesicular pH greater than intravesicular pH). 2. The H(+)-dependent overshooting transport of urea into the brush border membrane vesicles disappeared in the presence of H+ ionophore. 3. The initial velocity of H+ concentration gradient dependent uptake of urea into the brush border membrane vesicles was regulated by the saturation kinetics determined by the concentration of urea. The values of Km and Vmax, calculated as the kinetic parameters of urea transport by reciprocal plotting of the initial velocity of uptake and the concentration of urea, were 10.8 mM and 410 mumol/mg protein/10 sec, respectively. The above results indicate that a transport system which transports urea in exchange for H+ exists in human full-term placental microvillous membrane.
Biological Transport↗
Pharmacokinetics of vitamin K in mothers and children in the perinatal period: transplacental transport of vitamin K2 (MK-4).
In order to examine the pharmacokinetics of vitamin K2, vitamin K2 (MK-4) was intravenously injected into mothers, and its transfer to placental tissue and the fetuses was examined. While incorporation of vitamin K2 into placental tissue was relatively active, transfer of vitamin K2 to fetal blood (cord blood) was small. So it was indicated that vitamin K2 incorporated into placental tissue from maternal blood is initially stored in the placenta and then gradually released into the fetal blood. Since vitamin K deficiency has been pointed out, release of vitamin K2 into milk was also examined. When vitamin K2 (MK-4) was injected into mothers, the release of vitamin K2 into milk increased with time even after the plasma vitamin K2 concentration in maternal blood decreased. So the presence of a vitamin K2 concentrating mechanism in the mammary tissue was indicated.
Animals↗
Possible involvement of prostaglandins in psychological stress-induced responses in rats.
1. We investigated the effect of pre-treatment with intraperitoneal (I.P.) injection of indomethacin, an inhibitor of prostaglandin synthesis, on psychological stress-induced responses including cardiovascular, thermoregulatory and hormonal responses in free-moving rats. 2. Psychological stress was induced by cage-switch stress. After the rats were placed in the novel environment, blood pressure, heart rate and body temperature significantly increased. Plasma levels of adrenocorticotrophic hormone (ACTH) and prostaglandin E2 were significantly higher 30 min after exposure to stress, in comparison to normal levels. 3. Pre-treatment with I.P. indomethacin significantly suppressed the increases in body temperature induced by cage-switch stress, but had no effect on increases in blood pressure and heart rate induced by this stress. Indomethacin also significantly suppressed the increases in the plasma levels of ACTH and prostaglandin E2 induced by cage-switch stress. 4. The present results suggest that prostaglandins are involved in the development of hyperthermia and the ACTH response induced by psychological stress.
Adrenocorticotropic Hormone↗
ACTH release induced in rats by noradrenaline is mediated by prostaglandin E2.
1. We investigated the involvement of prostaglandin E2 in the development of the adrenocorticotrophic hormone (ACTH) response induced by noradrenaline (NA) in rats. 2. Intravenous (i.v.) injection of NA produced dose-dependent increases in the plasma concentration of ACTH and prostaglandin E2. However, pre-treatment with systemic administration of indomethacin, an inhibitor of prostaglandin synthesis, significantly suppressed this increase in plasma ACTH. 3. The i.v. injection of prostaglandin E2 significantly increased the plasma concentration of ACTH in a dose-dependent manner. In contrast, ACTH responses induced by the i.v. injection of prostaglandin E2 were significantly suppressed by systemic pre-treatment with anti-corticotrophin-releasing factor antibody (anti-CRF), although the plasma level of ACTH still increased in comparison to the basal level. 4. These results suggest that NA-stimulated prostaglandin release is involved in the ACTH response induced by NA. In addition, it is likely that CRF may be responsible for a portion of the ACTH response induced by i.v. injection of prostaglandin E2.
Adrenocorticotropic Hormone↗
Cloning and characterization of the Salmonella typhimurium ada gene, which encodes O6-methylguanine-DNA methyltransferase.
The ada gene of Escherichia coli encodes O6-methylguanine-DNA methyltransferase, which serves as a positive regulator of the adaptive response to alkylating agents and as a DNA repair enzyme. The gene which can make an ada-deficient strain of E. coli resistant to the cell-killing and mutagenic effects of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) has been cloned from Salmonella typhimurium TA1538. DNA sequence analysis indicated that the gene potentially encoded a protein with a calculated molecular weight of 39,217. Since the nucleotide sequence of the cloned gene shows 70% similarity to the ada gene of E. coli and there is an ada box-like sequence (5'-GAATTAAAACGCA-3') in the promoter region, we tentatively refer to this cloned DNA as the adaST gene. The gene encodes Cys-68 and Cys-320, which are potential acceptor sites for the methyl group from the damaged DNA. The multicopy plasmid carrying the adaST gene significantly reduced the frequency of mutation induced by MNNG both in E. coli and in S. typhimurium. The AdaST protein encoded by the plasmid increased expression of the ada'-lacZ chromosome fusion about 5-fold when an E. coli strain carrying both the fusion operon and the plasmid was exposed to a low concentration of MNNG, whereas the E. coli Ada protein encoded by a low-copy-number plasmid increased it about 40-fold under the same conditions. The low ability of AdaST to function as a positive regulator could account for the apparent lack of an adaptive response to alkylation damage in S. typhimurium.
Amino Acid Sequence↗
Factors associated with poor visual outcome in acute retinal necrosis.
We reviewed 22 consecutive patients (26 eyes) with acute retinal necrosis to elucidate whether there was any sign at an early stage to predict poor visual outcome. Final visual acuity of the patients fell into two groups, one worse than 20/600 (15 eyes) and the other better than 20/30 (11 eyes). The patients with poor visual outcome showed diffuse retinal arteritis or arterial obliteration which was associated with reduced amplitude of electroretinographic a and b waves and elevated levels of circulating immune complex, even at an early stage when retinal exudates were still localised to the peripheral fundus. The retinal exudates in these patients extended rapidly to the posterior pole. In contrast, the patients with good visual outcome showed retinal arteritis limited within retinal exudates throughout the course. These signs at an early stage can be used as prognostic factors to manage patients with acute retinal necrosis more constructively.
Adult↗
[Relationship between working-life satisfaction, health practices and primary symptoms/problems].
This study examined the relationship between Quality of Life (QOL) among workers of a major manufacturing company, health practices and primary symptoms/problems. To examine subjective assessment of the quality of life, we designed a comprehensive working-life satisfaction scale. Similarly we designed and assessed Health Practice Index (HPI) and scores for primary symptoms/problems. The results are summarized as follows: 1) Scores for primary symptoms/problems tended to be lower as the Health Practice Index (HPI) were higher. 2) Working-life satisfaction tended to be higher as scores for primary symptoms/problems were lower. 3) Working-life satisfaction tended to be higher as the Health Practice Index (HPI) were higher. The findings pointed to strong correlations between working-life satisfaction as a subjective index in order to assess the Quality of Life (QOL), the Health Practice Index (HPI) and scores for primary symptoms/problems.
Adult↗
Lifestyle and the right to clean air in public places (RCA) (Part 3). Relationship between opinions concerning RCA and personal lifestyle.
As a preliminary study to evaluate the possible roles of health education (education to acquire a healthy lifestyle) in supporting the development of a smokeless society, the relationship between opinions concerning the right to clean air in public places (RCA) and personal lifestyle as well as the relationships among three aspects of RCA and personal lifestyle were investigated in a randomly-selected sample (n = 887) of a population using a self-administered questionnaire. Relationships between opinions concerning RCA and lifestyle were analyzed within four subgroups of subjects defined by smoking status and sex. The results of these analyses indicated that opinions concerning RCA among women are related to knowledge of RCA and personal lifestyle while male opinions concerning RCA bear no statistical relationship to personal lifestyle. These results imply the possibility that knowledge of RCA and opinions concerning RCA among women can be effectively promoted by health education. The results of our analyses concerning the three aspects of RCA and personal lifestyle also indicate that attitudes toward RCA are positively correlated with factors other than knowledge and opinions concerning RCA; this implies the possibility that health education has but a limited impact on attitudes toward RCA.
Adult↗
Effects of irradiation on marrow stromal cells with respect to committed granulocyte-macrophage progenitor cells.
The effects of irradiation on the growth regulatory function of marrow stromal cells (MSC), and on the committed granulocyte-macrophage progenitor cells (GM-CFC), were investigated using a liquid culture system. CSF activity in the supernatant of irradiated MSC (0-900 rads) increased markedly with the increase of MSC irradiation dose. CSF-inhibitory activity in the supernatant of irradiated MSC (0-900 rads) also increased with the increase of MSC irradiation dose. Furthermore, the activity of exogenous CSF added to the supernatant of 900 rad-irradiated MSC was lost more slowly than that of non-irradiated MSC. These data suggest that irradiation affected CSF production, inhibitor production and consumption of CSF by MSC.
Animals↗
Aldehyde dehydrogenase deficiency, flush patterns and prevalence of alcoholism: an interethnic comparison.
A study was performed to verify that the prevalence of alcohol abuse and dependence in Formosan aborigines differs from that of Taiwanese (Chinese Han people), using analysis of aldehyde dehydrogenase (ALDH) isozymes and flush patterns on randomly sampled 70 Atayal, 66 Paiwan, 61 Yami and 94 Taiwanese subjects were studied. The activity of an isomer of ALDH having a low Km (ALDH-I) in hair roots was analysed by isoelectric focusing assay. The subjective experience of flushing response after alcohol ingestion was assessed. Results showed that the rate of ALDH-I deficiency in Taiwanese (51.1%) was significantly higher than in aborigines, i.e., 6.4%, 3.9%, and 0% in Atayal, Paiwan, and Yami subjects, respectively. The percentage occurrence of ALDH-I deficiency and prevalence of alcohol dependence in Taiwanese and aborigines were negatively correlated. The predominant pattern of self-reported flush response after alcohol use among aborigines was of slow onset. The flush response to alcohol ingestion was examined in relation to aldehyde metabolizing enzyme. Since alcohol sensitivity is an important factor in the development and maintenance of the alcohol ingestion habit in humans, our results support the hypothesis that there is a biological basis in the different rates of alcohol abuse and dependence among different ethnic groups.
Adult↗
Purine catabolites in cerebral interstitial fluid during progression of and recovery from ischemia.
The concentrations of purine catabolites in the cerebral interstitial fluid during progression of and recovery from ischemia were studied using brain microdialysis and high-performance liquid chromatography. Sealed 0.5-mm hollow dialysis fibers were stereotactically implanted into either the cerebral cortex or hippocampus of ketamine anesthetized gerbils and perfused with artificial cerebrospinal fluid at 2 microliters/min. Cerebral ischemia was induced by occlusion of the bilateral common carotid arteries. The reflectance spectra of oxy- and deoxyhemoglobin at the brain surface were monitored over the scalp to assess ischemia and confirm recirculation. Ischemia caused a rapid, 4.8-fold increase in the extracellular concentration of adenosine. The progressive increase in the concentration of adenosine, inosine, and hypoxanthine soon after recirculation is particularly interesting. The subsequent decrease in purine compound concentration was rapid for adenosine but more gradual for inosine and hypoxanthine. Calculated K values for adenosine deaminase and purine nucleoside phosphorylase were 0.045/min and 0.016/min, respectively. However, no xanthine, uric acid, or purine nucleotides were found in the perfusate. These observations indicated the presence of purine catabolites in the cerebral interstitial space as well as consecutive degradation and recycling involving the interconversion of purine compounds by biochemical metabolic pathways.
Animals↗
Intradural-extramedullary spinal cavernous angioma--case report.
An extremely rare case of intradural-extramedullary spinal cavernous angioma in a 65-year-old male is reported. The clinical presentation was recurrent episodes of subarachnoid hemorrhage (SAH). Magnetic resonance images disclosed the tumor at the 1st thoracic vertebra, without gadolinium enhancement. The tumor was tightly adhered to the cord surface and successfully removed microsurgically. The previous two reports of this unusual tumor also showed repeated SAH and the tumor attachment to the spinal cord or nerve roots. Intradural-extramedullary cavernous angioma possibly originates in the surface of the spinal cord or nerve root and then extends extraphytically.
Aged↗
[Epidemiological analysis of otitis media with effusion in children].
A study was conducted on 153 children with otitis media with effusion to assess risk factors for otitis media with effusion. Information was collected by questionnaire survey, clinical examination and audiological tests including tympanography. We investigated two groups of children with otitis media with effusion. Group 1 consisted of 70 children with otitis media with effusion who had not undergone myringotomy. Group 2 consisted of 83 children with otitis media with effusion who had undergone myringotomy. Bottle feeding and adenoidal hypertrophy occurred more frequently in Group 2 than in Group 1. These observations provide an epidemiologic and clinical basis for further investigations of otitis media with effusion.
Adolescent↗
[Summaries on the first draft of the EHC monographs in 1990].
The first drafts of the EHC monographs in 1990 were summarized into Japanese. The chemicals consist of hexachlorocyclopentadiene, trichlorfon, fenitrothion, methylparathion, trichloroethane, platinum and selected platinum salts, di(2-ethylhexyl)phthalate, partially halogenated chlorofluorocarbons, methyl ethyl ketone, and propachlor.
Animals↗
[Up-dating the references for environmental health criteria for anionic surfactants and preparation of its first draft].
The preparation of a EHC monograph for anionic surfactants was started in 1980. The chemicals consist of linear alkylbenzene sulfonate (LAS), alkyl sulfate (AS) and alkyl alpha-olefin sulfonate (AOS). Although a preliminary draft appeared in 1985, further works were stopped for 5 years. For the development of the preliminary draft, up-dating the references was performed by using on-line JICST data base from 1981 to 1990. The number of literature on LAS was 486. On the other hand the number on AS was about 1/5 that of LAS. In the case of AOS, only 20 literatures were retrieved. The literatures on LAS were many in the research field of environmental science and very few in the toxicology field.
Alkanesulfonic Acids↗
[Improvements of commentary work on the first drafts of the EHC monographs].
The EHC is historically most important among the activities of IPCS which was inaugurated in 1980, and its first draft is being circulated to IPCS contact points throughout the world. Comments and suggestions in improvements to the first draft of the EHC monograph is essential to the sound development of this document. Our suggestions on such improvements are the basis of this report.
Environmental Health↗