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Biomedical subjects

S Murai

Publications and source records attributed to S Murai.

At least 73 records · Page 4Linked to original sources
PubMed1995

Basal levels of noradrenaline, dopamine, 5-hydroxytryptamine, and acetylcholine in the submandibular, parotid, and sublingual glands of mice and rats.

The salivary glands of 5-week-old mice and rats were divided into submandibular, parotid, and sublingual and analysed to determine basal levels of the neurotransmitters noradrenaline (NE) and acetylcholine (ACh) and the possible neurotransmitters dopamine (DA) and 5-hydroxytryptamine (5-HT), using a combination of high-performance liquid chromatography coupled with coulometric and amperometric detection and a direct injection technique employing crude homogenate supernatants. In both species, levels of NE were higher in the submandibular than in the other salivary glands, whereas levels of ACh were higher in the mouse submandibular and the rat sublingual glands than in other glands. In all the salivary glands, levels of DA were markedly lower than those of other target substances. Levels of 5-HT were similar in all salivary glands. These results show that in mouse and rat salivary glands, species differences in neurotransmitter distribution are relatively small, whereas there are considerable differences in distribution between the salivary glands.

Acetylcholine↗
PubMed1995

Binding of myosin and its subfragment-1 with antibodies specific to the two heads of the myosin molecule.

It was shown by Miyanishi et al. [Miyanishi, T., Maita, T., Matsuda, G., and Tonomura, Y. (1982) J. Biochem. 91, 1845-1853] that the amino acid sequence around the reactive lysine residue is different between head B (Pi-burst head) and head A of the myosin molecule. Thus, we synthesized these two peptides, and prepared rabbit polyclonal antibodies against them. Each antibody bound strongly with both peptides. However, the binding of the antibodies with S-1 was inhibited by the peptide used for the antigen but unaffected by the non-antigen peptide, suggesting that only antibodies specific to each head can bind with S-1. Myosin was absorbed by either antibody A or B, which was immobilized on protein A in Staphylococcus aureus cells. However, half of S-1 was absorbed by each of the antibodies. The S-1 prepared showed about 0.5 mol of initial Pi-liberation per mol of S-1. The Pi-burst size of S-1 unbound to the immobilized anti-A antibody increased to almost 1 mol/mol S-1, while that of S-1 unbound to the anti-B antibody decreased to 0.15 mol/mol S-1. These results suggest the existence of two kinds of heads in the myosin molecule.

Amino Acid Sequence↗
PubMed1995

13C-UBT using an infrared spectrometer for detection of Helicobacter pylori and for monitoring the effects of lansoprazole.

The stable isotope [13C]-labeled urea breath test (13C-UBT) is very useful for detecting Helicobacter pylori. Conventionally, a mass spectrometer is used to measure the presence of 13CO2 in breath. However, this technique is complex and expensive. Therefore, we carried out the 13C-UBT using an easy-to-operate infrared spectrometer, and we studied its usefulness. The 95 subjects included 35 patients with gastric ulcers, 32 with duodenal ulcers, 13 with gastroduodenal ulcers, some patients with nonulcer gastroduodenal disease, and normal controls. The 13C-UBT was negative in normal controls and positive in 86 of 91 (95%) patients with illness. Peaks appeared 15 to 30 min after [13C]urea administration. The 33 patients who were 13C-UBT-positive were then given lansoprazole 30 mg/day and the 13C-UBT was repeated after 8 to 16 weeks. Lansoprazole was found to be effective in patients who exhibited peak 13CO2 values that were at least two-thirds less than the pretreatment values. This effect was seen in 16 patients (48%), 13 of whom (81%) had gastric ulcers. Thirteen of the 17 patients (76%) who exhibited no effect had duodenal ulcers, and there were clear treatment response differences between the two types of ulcers.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1995

[Three simple maze tests employing mice housed in maze apparatuses].

This report deals with three different maze methods using spontaneous learning behavior. Forty-eight mice housed in an apparatus with a multiple maze mastered the maze task on the 5th day after the start of housing. Then they were divided into four groups, and two of the groups were treated with AF64A (3.5 nmol, i.c.v.) or trimethyltin (TMT, 3 mg/kg, p.o.), and the other two groups were treated with the vehicle as the respective control. Seven days after the treatment, their memory retrieval was tested. Subsequently, the same mice were housed in the apparatus with a T-maze. After the finish of the experiment using the T-maze, they were housed in the apparatus with an eight arm radial maze. The control groups mastered the T-maze task with a 3-sec delay on the 4th day after the start of housing and the radial maze task on the 10th day after the start of housing. Both the treatments lowered the performance in all maze tasks. These results show that the mice housed in the apparatus with maze learned to negotiate the maze spontaneously, and the apparatuses are useful for estimating memory in mice with little effort.

Animals↗
PubMed1995

Histopathological reaction of calcium phosphate cement in periodontal bone defect.

In this study, we evaluated the osteoconductivity of calcium phosphate cement (CPC) as compared to that of a current hydroxyapatite-based material (AP) by implanting the materials in surgically formed defects in the jaws of dogs. One month post-operation, slight inflammatory reactions were observed in tissue areas adjacent to either CPC mass or AP. Three months after operation, the CPC mass-filled defects were covered with periosteum and bone tissues. The CPC mass in the defects was partially replaced by newly formed bone. In bone defects filled with AP, most of the interparticle space was filled with connective tissues including bone tissues. Six months post-operation, the CPC mass-filled defects were covered with periosteum and new bone, and most of the CPC mass was replaced by bone. Interparticle spaces of AP were filled with connective tissues and bone tissues.

Alveolar Bone Loss↗
PubMed1995

Root resorption associated with hydroxyapatite particles: a case report.

A case report of an unusual root resorption reaction associated with a graft of hydroxyapatite particles is presented. The hydroxyapatite particles were grafted to treat vertical infrabony defects at the distal aspect of the maxillary left canine and on the mesial side of the mandibular right first molar. The graft sites were monitored at maintenance visits. Root resorption was observed radiographically 9 to 10 months after grafting. The lesions were restored with a light-cured glass-ionomer cement and/or a resin composite. Possible etiologic factors associated with this condition are discussed.

Bone Substitutes↗
PubMed1995

A modified method for quantitative measurements of cholinergic and adrenergic sialogogue-induced salivation in mice.

A modified procedure based on that reported by Richter is described for the quantitative measurement of salivation induced by sialogogues in mice. As a new immobilizing technique for mice, the present method uses a combination of light anesthesia produced by a low dose (1.0 g/kg, i.p.) of urethane and a fixing plate, instead of deep anesthesia induced by a high dose (1.8 g/kg, i.p.) of urethane. Unlike Richter's method, the immobilizing technique described here did not potentiate the toxicity of sialogogues and hence no mice died within 48 h after the end of the experiment. This method could easily measure salivation induced by cholinergic agonists (pilocarpine and bethanechol) and adrenergic agonists (phenylephrine and isoproterenol), dose-dependently. Thus, the present method may be useful for studying salivation responses induced by various types of sialogogues under less toxic experimental conditions in mice.

Animals↗
PubMed1994

Effects of nefiracetam on deficits in active avoidance response and hippocampal cholinergic and monoaminergic dysfunctions induced by AF64A in mice.

The effects of nefiracetam [DM-9384; N-(2,6-dimethyl-phenyl)-2-(2-oxo-pyrrolidinyl)acetamide] and of phosphatidylcholine on a step-up active avoidance response, locomotor activities and regional brain cholinergic and monoaminergic neurotransmitters in AF64A-treated mice were investigated. Intracerebroventricular (i.c.v.) injection of AF64A (ethylcholine mustard aziridinium ion; 8 nmol/ventricle) impaired acquisition and retention of the avoidance task, and increased vertical and horizontal locomotor activities. Regional levels of acetylcholine, noradrenaline, 3-methoxy-4-hydroxyphenylglycol (MHPG), 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) were significantly decreased and homovanillic acid (HVA) levels were increased in the hippocampus but not in the septum, cerebral cortex or striatum of AF64A-treated animals. Administration of nefiracetam (3 mg/kg, p.o.) twice daily for 9 days to AF64A-treated animals ameliorated the deficit in active avoidance response in addition to attenuating the increase in locomotor activities. In parallel with these behavioural effects, nefiracetam reversed AF64A-induced alterations in the hippocampal profiles of cholinergic and monoaminergic neurotransmitters and their metabolites. In contrast, administration of phosphatidylcholine (30 mg/kg, p.o.) twice daily for 9 days had no significant effect on the deficit in active avoidance response, despite significantly reversing the decrease in acetylcholine levels in the hippocampus. These results indicate that the effects of nefiracetam on AF64A-induced behavioural deficits are probably due to its ability to facilitate both cholinergic and monoaminergic neurotransmitter systems.

Acetylcholine↗
PubMed1994

MKC-231, a choline uptake enhancer, ameliorates working memory deficits and decreased hippocampal acetylcholine induced by ethylcholine aziridinium ion in mice.

The effects of acute and chronic administration of MKC-231, a new choline uptake enhancer, and two other nootropic agents, linopiridine (Dup 996) and tetrahydroaminoacridine (THA) on working memory deficits and decreased hippocampal acetylcholine (ACh) content were studied in a delayed non-matching to sample task, using a T-maze, in ethylcholine aziridinium ion (AF64A)-treated mice. Treatment with AF64A (3.5 nmol, i.c.v.) produced memory deficits and decreased hippocampal ACh content. In acute behavioral experiments, MKC-231 and THA had no significant effect on AF64A-induced memory deficits at any doses tested (0.3, 1.0 and 3.0 mg/kg), whereas Dup 996, at a dose of 1.0 mg/kg, significantly improved memory deficits. In chronic experiments, MKC-231 improved memory deficit at all doses tested (0.3, 1.0, or 3.0 mg/kg p.o., once daily for 11 days) and Dup 996 did so only at a dose of 3.0 mg/kg, whereas THA did not improve memory deficit at any doses tested. In acute neurochemical experiments, MKC-231 and THA did not reverse the AF64A-induced hippocampal ACh depletion. Dup 996, however, further decreased hippocampal ACh content compared to that in the AF64A-treated group. In chronic experiments, MKC-231 significantly reversed hippocampal ACh depletion at doses of 0.3 and 1.0 mg/kg, whereas neither Dup 996 nor THA reversed hippocampal ACh depletion at any doses tested. These results indicate that MKC-231 improved the AF64A-induced working memory deficit and hippocampal ACh depletion, probably by recovering reduced high-affinity choline uptake and ACh release.

Acetylcholine↗
PubMed1994

Radial arm maze behavior in mice when a return to the home cage serves as the reinforcer.

Male ddY mice were housed in a cage with an eight arm radial maze apparatus for 6 h a day. A water bottle was placed at the central platform. The end of each arm ran to the home cage through a guillotine door (G). Food was placed at the home cage. During the housing in the apparatus, one G was raised and the remaining seven G were lowered. The raised G was changed every 45 min in random order. Mice housed in this apparatus learned efficient strategy to return the home cage by trial and error. When they chose the arm in which the G was lowered on their way to the home cage from the platform, they returned to the platform, then chose a different arm until they were able to enter the home cage. The mice housed in this apparatus mastered the radial maze task on the 7th day. When scopolamine (SCO) was injected, SCO butylbromide had no effect on performance, but SCO hydrobromide (0.2 and 0.4 mg/kg) impaired working memory, dose dependently. These results show that the apparatus is useful for ease in estimating working memory in mice without the use of severe food or water deprivation.

Animals↗
PubMed1994

Rapid HPLC assay with coulometric detection for norepinephrine and 3-methoxy-4-hydroxyphenylglycol in the mouse brain.

For the rapid assay of norepinephrine (NE) and its major metabolite, 3-methoxy-4-hydroxyphenylglycol (MHPG) in the mouse brain, we developed a simple method using isocratic HPLC with coulometric detection. This method permits NE and MHPG assay within 5 min in one chromatographic run. Within-run coefficients of variation for NE and MHPG in the working standard solution were 0.8% and 0.6% (n = 50), respectively. The detector responses were linear from 0.025 to 100 pmol for NE and from 0.05 to 100 pmol for MHPG in the working standard solution. Using this method, the NE and MHPG concentrations were measured in discrete brain areas of the mouse prior treatment with or without alpha-methyl-p-tyrosine or N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP4).

Adrenergic Agents↗
PubMed1994

Ethanol injection sclerotherapy for Baker's cyst, thyroglossal duct cyst, and branchial cleft cyst.

Six patients with Baker's cysts, 3 with branchial cleft cysts, and 2 with thyroglossal duct cysts were treated with percutaneous aspiration and absolute ethanol sclerotherapy using a 7-French pigtail catheter. Cystography was performed before ethanol injection to confirm that there was no extravasation and that it was a monocystic lesion. One recurrence of a Baker's cyst was revealed in follow-up examinations, which ranged from 11 months to 36 months (mean, 25 months). The major complication of hypoesthesia of the popliteal region was observed in 1 patient treated for Baker's cyst. The results of this series suggest that ethanol sclerotherapy is the treatment of choice for Baker's cyst, branchial cleft cyst, and thyroglossal duct cyst.

Adolescent↗
PubMed1994

The inhibitory effect of endotoxins on growth of human cell lines.

A study was conducted to examine the effect of endotoxin present in periodontal pockets on the proliferation and attachment of human cell lines on the culture plates (Ca9-22 and gingival fibroblasts). The endotoxin was collected from periodontal pockets of anterior teeth in patients with periodontal disease by subgingival irrigation with sterilized distilled water. The solutions obtained were then subjected to hot phenol-water extraction. The collected endotoxin from periodontal pocket and four other kinds of endotoxin obtained commercially as positive controls were added to cell cultures and the numbers of viable cells on the culture plates were counted. Among the commercially available endotoxins used in this study, only 500 micrograms/ml of endotoxin derived from Escherichia coli 0111:B4 significantly decreased the number of attachment cells of Ca9-22 and gingival fibroblasts on the culture plates. Endotoxin from periodontal pockets at 5 micrograms/ml also significantly decreased the numbers of attachment cells of both cell lines.

Adult↗
PubMed1994

Subgingival plaque formation on single and polycrystal aluminum ceramics.

A study was conducted to investigate subgingival plaque formation on two types of dental implant material in the human oral cavity. Fifteen teeth affected by severe periodontitis and scheduled for extraction in five patients were selected. After thorough root planing, inlay cavities were prepared from the gingival margin to 5 mm subgingivally. Then, rectangular test specimens (polycrystal aluminum ceramic (P), single-crystal aluminum ceramic (S)) or a control dentin specimen (D) were installed in gold inlays, which were placed in the inlay cavities and left for 3, 7 or 21 d. As a consequence, 4 mm of the surface of each specimen was exposed to the environment of the periodontal pocket. After each test period, the specimens were removed from the inlays and examined by scanning electron microscopy (SEM). The results suggested that S is a more suitable dental implant material than P from the viewpoint of clinical application because of its lower degree of plaque accumulation.

Adult↗
PubMed1993

Alpha-sialyl cholesterol reverses AF64A-induced deficit in passive avoidance response and depletion of hippocampal acetylcholine in mice.

1. The effect of alpha-sialyl cholesterol (alpha-SC; alpha-D-N-acetylneuraminyl cholesterol) on disturbances of the central cholinergic system induced by ethylcholine mustard aziridinium ion (AF64A) and by scopolamine were studied by means of a step-down passive avoidance response and locomotor activities in mice. The levels of acetylcholine (ACh) in certain regions of the brain were measured to assess the neurochemical recovery promoted by alpha-SC. 2. Treatment with AF64A (2.5, 5 and 10 nmol, i.c.v.) impaired the 24 h retention latencies of animals in a dose-dependent manner, and scopolamine (0.5 mg kg-1, i.p.) also impaired the retention performance. Administration of alpha-SC (1 and 4 mg kg-1, p.o.) once daily for 13 days improved the retention performance in AF64A-treated animals in a dose-dependent manner, but not in the scopolamine-treated animals. 3. Treatment with AF64A (2.5, 5 and 10 nmol, i.c.v.) and scopolamine (0.5 mg kg-1, i.p.) increased vertical and horizontal locomotor activities. alpha-SC dose-dependently attenuated the increase in locomotor activities induced by 2.5 nmol of AF64A, but not the locomotor activities caused by 5 or 10 nmol of AF64A, or scopolamine (0.5 mg kg-1, i.p.). 4. The deficit retention performance of AF64A-treated animals was associated with depletion of ACh levels in the hippocampus, but not in the septum or cerebral cortex. Administration of alpha-SC to AF64A-treated animals dose-dependently reversed the depletion of ACh levels in the hippocampus. 5. The results indicate that alpha-SC had significant effects after oral administration of AF64A-treated animals. The behavioural recovery promoted by alpha-SC may be based on the reversal of ACh depletion in the hippocampus.

Acetylcholine↗
PubMed1993

[A method employing housing in a radial maze apparatus for estimating working memory in mice: effects of scopolamine and delay upon maze performance].

Male ddY mice were housed in a 4-, 6-, or 8-arm radial maze apparatus for 6 hr a day and then removed to a normal cage for fasting until the next day's trial. A water bottle was placed at the central platform. The end of each arm ran to the home cage through a guillotine door (G). Food was placed in the home cage. During the housing in the apparatus, one G was opened, and the remaining Gs were shut. The opened G was changed in random order during the housing period of 6 hr. At the beginning of the trial, all Gs were shut. The mouse was placed on the platform and was permitted to choose the arms until it chose all arms. When the mouse chose the last arm, the G was opened to allow stepping into the home cage. The mice housed in these apparatus learned to go to the home cage without entering already chosen arms within 4-6 days. Scopolamine (0.2 and 0.4 mg/kg, i.p.) impaired the maze performance. A 1- to 4-min delay impaired the performance slightly, but did not show any significant effect depending on the delay intervals. These results suggest that the apparatus is a useful and easy method for estimating working memory and the drug effects thereon in mice.

Animals↗
PubMed1993

Effects of Nd:YAG laser radiation on removal of a root surface smear layer after root planing: a scanning electron microscopic study.

A scanning electron microscopy (SEM) study was conducted to evaluate the effects of Nd:YAG laser radiation on removal of a root surface smear layer after root planing in comparison with citric acid treatment. The experimental materials were 15 human teeth affected by severe periodontal disease, which were extracted because of a hopeless prognosis. The teeth had at least 5 mm of attachment loss on the proximal surface tested. After removing all visible calculus using an ultrasonic scaler, each proximal surface was vigorously scaled and root planed with a Gracey curet. Thirty specimens were cut from the root-planed proximal surfaces and assigned randomly to one of two groups: Group A (25 specimens) was divided into 5 subgroups and irradiated with a Nd:YAG laser, using non-contact delivery (3 mm beam diameter, distance from the tip to the specimen 5 cm), at a measured power of 20 W for 0.3, 0.5, 1.0, 2.0, or 3.0 seconds corresponding to energy densities of 84.93, 141.54, 283.09, 566.17, or 849.26 J/cm2; Group B (5 specimens) was not irradiated, but treated for 3 minutes with saturated citric acid (pH 1). The center of each specimen in Group A was used as the experimental area (Exp A) treated by laser irradiation and the peripheral area of the specimen served as a control (Cont A). In Group B, one half of the specimen was used as the experimental area (Exp B) treated by citric acid and the other half served as a control (Cont B). The specimens were then fixed and examined by SEM. The surface of the root-planed specimens (Cont A and B) was irregular, corresponding to the presence of a smear layer, and had an amorphous appearance. Both root surfaces of Exp A and B exhibited clear orifices of dentinal tubules and intertubular dentin without a smear layer. Although the root surface of Exp A showed clear orifices of dentinal tubules with a flat morphology, the root surface of Exp B showed widened funnel-shaped dentinal tubule orifices with a fibrillar, mat-like morphology. The present results indicate that Nd:YAG radiation effectively removes the smear layer, uncovers dentinal tubules, and exposes collagen fibers on the root surface without widening the orifices of dentinal tubules after root planing.

Aluminum Silicates↗