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Biomedical subjects

H Yanase

Publications and source records attributed to H Yanase.

At least 73 records · Page 4Linked to original sources
PubMed1993

Origin of intracellular Ca2+ elevation induced by in vitro ischemia-like condition in hippocampal slices.

Microfluorometry was used to investigate the origin of intracellular Ca2+ ([Ca2+]i) elevation in field CA1 of gerbil hippocampal slices perfused with a glucose-free physiological medium equilibrated with a 95% N2/5% CO2 gas mixture (standard in vitro ischemia-like condition). Large [Ca2+]i elevation was detected about 4 min after the beginning of standard in vitro ischemia-like condition, which was accompanied with a negative shift of extracellular DC potential. When slices were perfused with Ca(2+)-free in vitro ischemia-like medium, large [Ca2+]i elevation was observed about 3.5 min after the beginning of Ca(2+)-free in vitro ischemia-like condition, however, the increase in [Ca2+]i was more gradual and of a lesser extent compared with that detected in the slices perfused with the standard in vitro ischemia-like medium that contained Ca2+. When slices were perfused with the Ca(2+)-free in vitro ischemia-like medium that contained dantrolene (50 microM) which is known to prevent Ca(2+)-induced Ca2+ release from intracellular Ca2+ stores, the increase in [Ca2+]i was more gradual and of a lesser extent compared with that detected in the slices perfused with the Ca(2+)-free in vitro ischemia-like medium that did not contain dantrolene. These results indicate that large [Ca2+]i elevation induced by in vitro ischemia-like condition in field CA1 of the hippocampus was caused by both Ca2+ influx from extracellular space and Ca2+ release from intracellular Ca2+ stores, and that a part of the Ca2+ release was due to Ca(2+)-induced Ca2+ release from intracellular Ca2+ stores.

Animals↗
PubMed1993

The sedative effect of intranasal midazolam administration in the dental treatment of patients with mental disabilities. Part 1. The effect of a 0.2 mg/kg dose.

The purpose of this study was to determine the sedative effect of a 0.2 mg/kg dose of midazolam, administered intranasally, prior to performing various restorative dental procedures on a group of mentally disabled patients under local anesthesia and nitrous oxide/oxygen analgesia. Twenty-one patients, aged 4 to 21 years, all of whom had previously exhibited highly combative and resistant behavior toward dental treatment under local anesthesia, were sedated with 0.2 mg/kg midazolam. Only patients assessed as ASA anesthesia status I or II were admitted to the study. After administering the midazolam, each patient was allowed to rest before initiating the dental procedures. Behavioral patterns during the various procedures were rated on a behavioral rating scale of 1-7. Each patient served as his or her own control, comparing behavior with or without intranasal midazolam. The results showed a marked improvement in behavioral patterns after administration of intranasal midazolam. Ratings on a scale of 1-7 were noted as "markedly effective" and "effective" for 69.2% of those patients who received infiltration injection anesthesia, 93.8% under rubber dam, 76.2% during cavity preparation, 84.2% for restoration placement and 87.5% during pulpotomy procedures. The majority of patients were discharged within 150 minutes of intranasal instillation. Further studies are indicated to ascertain the most appropriate dose of intranasally administered midazolam.

Administration, Intranasal↗
PubMed1992

Cloning and sequence analysis of the StsI restriction-modification gene: presence of homology to FokI restriction-modification enzymes.

StsI endonuclease (R.StsI), a type IIs restriction endonuclease found in Streptococcus sanguis 54, recognizes the same sequence as FokI but cleaves at different positions. A DNA fragment that carried the genes for R.StsI and StsI methylase (M.StsI) was cloned from the chromosomal DNA of S.sanguis 54, and its nucleotide sequence was analyzed. The endonuclease gene was 1,806 bp long, corresponding to a protein of 602 amino acid residues (M(r) = 68,388), and the methylase gene was 1,959 bp long, corresponding to a protein of 653 amino acid residues (M(r) = 76,064). The assignment of the endonuclease gene was confirmed by analysis of the N-terminal amino acid sequence. Genes for the two proteins were in a tail-to-tail orientation, separated by a 131-nucleotide intercistronic region. The predicted amino acid sequences between the StsI system and the FokI system showed a 49% identity between the methylases and a 30% identity between the endonucleases. The sequence comparison of M.StsI with various methylases showed that the N-terminal half of M.StsI matches M.NIaIII, and the C-terminal half matches adenine methylases that recognize GATC and GATATC.

Amino Acid Sequence↗
PubMed1992

Acidic fibroblast growth factor delays in vitro ischemia-induced intracellular calcium elevation in gerbil hippocampal slices: a sign of neuroprotection.

Using microfluorometry, effects of acidic fibroblast growth factor (aFGF) on the in vitro ischemia-induced intracellular calcium elevation were investigated in gerbil hippocampal slices at 35 degrees C. When slices were superfused with hypoxic and glucose-free medium, the mean latency of the in vitro ischemia-induced calcium elevation was 209 +/- 51 s. The addition of aFGF in medium (25 micrograms/l) delayed the calcium elevation throughout the experiments: the mean latency was 541 +/- 94 s. This retardation in calcium elevation may be indicative of neuroprotective nature of aFGF.

Animals↗
PubMed1992

Intracellular and extracellular chloride ions in the horizontal cells of the stingray retina.

Intracellular and extracellular concentrations of chloride ([Cl-]i, [Cl-]o) ions in the horizontal cells of the stingray retina were studied by means of ion-selective microelectrodes. The electrodes used were of the double-barreled type and Corning's #477315 resin was used as the exchanger. The average [Cl-]o and [Cl-]i in the L-type cells were 320 and 130 mM, respectively (n = 37), and the equilibrium potential (ECl) was calculated as -23.3 mV. In some cases, dark membrane potentials were more positive than the ECl. With white light stimulus, the membrane hyperpolarized to a more negative level than ECl. Based on the experiments described above, the hypothesis that the hyperpolarizing response of horizontal cells is due to the permeability change of the membrane to chloride ion was excluded in the stingray retina.

Animals↗
PubMed1991

The effect of K(+)-conductance-blocking substances on the occurrence of retinal spreading depression.

Retinal spreading depression (SD) has been thought to be generated by an abnormal increase in [K+]o in the inner plexiform layer. When a retina isolated from bullfrog was immersed in a medium conditioned for SD (low Cl- Ringer's solution), spontaneous SDs periodically occurred at a fixed interval in the dark. The effect of K(+)-conductance blocking substances (Ba2+, Cs+, TEA and 4-AP) on the occurrence of SD was studied using the concomitant changes in the field potential (spreading depression potential; SDP) as an index. These substances increased the frequency of occurrence and decreased the amplitude of the potential. According to the Müller cell theory of SDP, an increase in [K+]o depolarizes the Müller cells and the resulting extracellular current generates the potential change. Since the small amplitude of the SDP reflects the decreased K+ current, it may be said that the K(+)-buffering capacity of the Müller cells was partially reduced by the substances and that the frequency of the SD occurrence consequently increased in order to clear accumulating [K+]o from neurons with the decreased buffering capacity. The present results lend a good support to the current Müller cell theory for the occurrence of SDP.

4-Aminopyridine↗
PubMed1991

Cloning, sequencing, and characterization of the intracellular invertase gene from Zymomonas mobilis.

The structural gene for the intracellular invertase E1 of Zymomonas mobilis strain Z6C was cloned in a 2.25-kb DNA fragment on pUSH11, and expressed in Escherichia coli HB101. The enzyme produced by the E. coli carrying pUSH11 was purified about 1,122 fold to homogenicity with a yield of 4%. The molecular weight and substrate specificity of the enzyme were identical with those of the intracellular invertase E1 from Z. mobilis. The nucleotides of the cloned DNA were sequenced; they included an open reading frame of 1,536 bp, coding for a protein with a molecular weight of 58,728. The N-terminal amino acid sequence predicted was identical with the sequence of the first 20 N-terminal amino acid residues of the protein obtained by Edman degradation. Comparison of the predicted amino acid sequence of E1 protein with those of the four other known beta-D-fructofuranosidases from Escherichia coli, Bacillus subtilis, and Saccharomyces cerevisiae indicated a stronger homology in the N-terminal portion than in the C-terminal portion.

Amino Acid Sequence↗
PubMed1990

[The image on dental environment in mothers. A comparison of handicapped and normal children's mother].

The purpose of the present study was to investigate the image on the dental environment of the mothers of handicapped and normal children. To investigate the image on dental environment, the Semantic Differential Method was applied to mothers of 42 handicapped and 35 normal children. They rated 4 items--'dentist', 'my child', 'dental treatment' and 'dental operating room'--on the adjective-scales 12 pairs. The results of this study were summarized as follows: 1. In comparing the mean of the rating score, it observed that the mothers of handicapped children have a more positive image than the mothers of normal children. This tendency appeared more clearly at 'dental treatment' and 'dental operating room'. 2. By principal factor analysis and varimax rotation, 2 factors were extracted from every 4 items. 3. Factor scores at factor 1 and factor 2 of the mothers of handicapped children were different from those of the mothers of normal children. The mothers of handicapped children had views that a dental treatment is ease and acceptable, and that a dental operating room is comfortable and safe.

Attitude to Health↗
PubMed1989

[Dental treatment and the prognosis for handicapped children].

We analysed a survey made on oral examinations at the first visit, the kind of dental treatment and the prognosis. The subjects were 77 handicapped children who received dental treatment at the pedodontic clinic of the Aichi-Gakuin University Dental Hospital and periodic examinations after the completion of dental treatment. The average age of the subjects was 7.4 (2.11 to 16.7 years old). (1) At the first visit, the mean number of untreated decayed teeth was 7.1 for the group of children who received dental treatment without general anesthesia, and 12.0 for the group of children who received dental treatment with general anesthesia. And the rate of untreated decayed teeth was 40.1% of the deciduous and 21.0% of the permanent teeth for the group of children who had received dental treatment without general anesthesia, and 65.5% of the deciduous and 34.2% of the permanent teeth for the group of children who had received dental treatment with general anesthesia. (2) For the group of children who received dental treatment without general anesthesia, restoration was performed on 62.5% of the deciduous and 87.5% of the permanent teeth; the remaining 37.5% of the deciduous and 12.5% of the permanent teeth were extracted. Endodontic treatment was performed on 20.6% of the deciduous and 8.9% of the permanent teeth. (3) For the group of children who received dental treatment with general anesthesia, restoration was performed on 57.0% of the deciduous and 95.1% of the permanent teeth; the remaining 42.9% of the deciduous and 4.9% of the permanent teeth were extracted. Endodontic treatment was performed on 25.3% of the deciduous teeth and 12.2% of the permanent teeth. (4) In the case of restorative treatment, the highest incidence was in metal crowns on the deciduous teeth, and amalgam fillings in the permanent teeth for the groups of children who received dental treatment with or without general anesthesia. In the case of endodontic treatment, the highest incidence was in pulp amputation for the groups of children who received dental treatment with or without general anesthesia. (5) During the past year of completed dental treatment, unsuccessful cases were 5.4% for the restorative treatment and 0% for the endodontic treatment for the group of children who received dental treatment without general anesthesia; unsuccessful cases were 14.1% for the restorative treatment and 4.1% for the endodontic treatment for the group of children who received dental treatment with general

Adolescent↗
PubMed1989

[The behavior of mothers during dental treatment for their handicapped children. 1. Relationship between mothers' behavior and child patients' factors].

The purpose of this study was to find out factors which determine whether or not mothers of handicapped children chose to be with their children while receiving dental care. The subjects were 46 pairs consisting of a handicapped child and his or her mother who came to the pedodontic clinic of Aichi-Gakuin University Dental School. Such factors of the patients as the various abilities of the patients, their behavior and other items were surveyed with a behavior evaluation. These factors are considered to be related to determining the behavior of the mothers. The results of the survey are summarized as follows: 1. Patients whose mothers chose to be with them tended to be slightly inferior in basic language use and mouth rinsing ability, when compared with patients whose mothers chose to stay in the waiting room. 2. Patients who were autistic more often had mothers who chose to be with them than patients with other disabilities. 3. Patients whose mothers chose to be with them got higher Behavior Evaluation Scores in all dental care situations so that they tended not to adapt to dental care, when compared with patients whose mothers chose to stay in waiting room. 4. From the analyses of Quantification Type II, a height correlation ratio was obtained in the distinction efficiency of the mothers' behavior. Also the behavior of the mothers could be predicted by the factors of the children. 5. There were four factors present in those handicapped children which are considered to have determined their behavior of the mothers: the kind of disability, verbal expression ability, mouth rinsing ability and adaptation to dental care.

Adult↗
PubMed1989

[Clinical effects of training in behavior management on handicapped patients in dentistry].

Behavior-therapeutic training was applied to patients who were not cooperative in dental surroundings and could not be managed for dental treatment. The training was continued from the first to the final visit and also at periodical checkups. The clinical effects of training were evaluated. The subjects were 150 handicapped child patients who visited the pedodontic clinic of Aichi-Gakuin University. The patients were classified into two groups according to the degree of cooperation regarding dental treatment during the first visit; 1) the slightly uncooperative group and 2) the uncooperative group. The results were as follows: 1. Training applied prior to actual dental treatment caused 48.7 per cent of the patients to accept routine dental treatment. 2. When N2O/O2 inhalation sedation was added to the training, 79.0 per cent of the slightly uncooperative group were able to accept dental treatment under conseious situation, and 46.0 per cent of the uncooperative group were able to accept it. 3. Continuous training caused 60.7 per cent of all patients to become cooperative. 4. Continuous training was effective with 95.3 per cent of the patients who experienced N2O/O2 sedation, 76.8 per cent of the patients who experienced general anesthesia and 71.2 per cent of the patients who experienced routine dental treatment.

Anesthesia, Dental↗
PubMed1989

[Behavior of mothers during dental treatment for their handicapped children. 1. Relationship between the mothers' behavior and the image to dental environment and self-consciousness].

The purpose of this study was to find out factors by which mothers of handicapped children chose whether to be with their children while receiving dental treatment or not. The questionnaires from mothers of 42 handicapped children were examined. Factors on the part of the mothers such as their views on the dental environment, their egogram, and the reasons of the mothers' behavior were surveyed. The results of this study were summarised as follows: 1. Both the group of the mothers with their children in the operating room and the group of the mothers not with their children had views of slightly good for a dentist, her child, and a dental operating room. These views were examined by the Semantic Differential Method. 2. Both types of mothers had views of slightly bad for dental treatment. 3. The group of mothers not with their children tended to have a good view of her child and a dental operating room, when compared with the group of mothers with their children. 4. From the analyses of the egogram of the Tokyo university' test, an AC (Adapted Child) was drawed as the factor, in relation to mothers' behavior. 5. The reasons why the mothers chose to be with their children were as follows: the children would have no anxiety, the mothers were apprehensive for their children, the children were not able to speak, and so forth. 6. The reasons why the mothers chose to stay in waiting room were as follows: there will be no reliance on the mothers and child will not be become spoiled, and they should do everything by themselves, children can manage to be treated alone, and so forth.

Adult↗
PubMed1987

[Endothelium-derived relaxation of canine uterine artery and arachidonic acid metabolism].

Vascular responses to acetylcholine (ACh) and calcium ionophore A23187 were studied in the rings of the canine uterine arteries. Using uterine arteries of mature female mongrel dogs, ring-form specimens were prepared under a microscope. According to the Magnus' method the specimen was vertically fixed in Krebs-Henseleit solution and with a force-displacement transducer the isometric tension was determined. ACh and A23187 caused dose-dependent relaxation in the control, but it did not cause a response in endothelium-denuded preparations during contractions evoked by 3 X 10(-7)M norepinephrine. When pretreated with indomethacin (3 X 10(-6)M), a cyclooxygenase inhibitor, the maximal relaxation response induced by ACh was 73.35 +/- 14.53%, and pD2 values of 7.09 +/- 0.54, showing no difference from the untreated ones. On the other hand, preincubation with lipoxygenase inhibitors, nordihydroguaiaretic acid (NDGA) (3 X 10(-5)M) and AA861 (2 X 10(-5)M), prevented ACh-induced relaxation. The same trend was noted with the relaxation response induced by A23187. These results suggest that endothelium-derived relaxation of the canine uterine artery by ACh and A23187 may be mediated by a noncyclooxygenase metabolite(s). It was speculated that such inhibition of releasing EDRF has certain effects on the pathogenesis of toxemia and IUGR.

Acetylcholine↗
PubMedDate not supplied

Ischemic neuronal damage. How does mild hypothermia modulate it?

The significance of mild hypothermia as a therapeutic measure for ischemic brain damage is presented on the basis of different experimental results. An extracellular glutamate surge, a sustained activation of N-methyl-D-aspartate (NMDA) receptors, and an enhancement of DNA binding activity to transcription factor AP-1, all being key items directly linked to excitotoxic neuronal damage, are deeply affected by slightly lowering temperature (mild hypothermia [MH]). The cellular mechanism of MH seems rather nonspecific but tends to collectively involve these key items rendering neurons resistant to ischemic damage. Clinical application of MH should be a great challenge to relieve deadly effects on central neurons.

Animals↗