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Biomedical subjects

M Kishi

Publications and source records attributed to M Kishi.

At least 127 records · Page 7Linked to original sources
PubMed1991

Pharmacological characteristics of choline transport system in mouse cerebral cortical neurons in primary culture.

The characteristics of [3H]choline transport with high affinity were investigated using primary cultured neurons obtained from the mouse cerebral cortex. [3H]Choline uptake was saturable as a function of extracellular [3H]choline concentration. Analysis by Lineweaver-Burk plot revealed that [3H]choline was transported into neurons by a high affinity transport system with a Km value of 19.8 +/- 0.8 microM and Vmax value of 0.334 +/- 0.022 nmol/mg protein/min. This high affinity transport of [3H]choline was significantly inhibited by the withdrawal of sodium from the incubation medium, incubation at low temperature (4 degrees C) and addition of metabolic inhibitors such as monoiodoacetate. These results indicate that the high affinity [3H]choline uptake in primary cultured neurons is sodium- and energy-dependent. Hemicholinium-3 also showed a competitive inhibition on the [3H]choline transport. Depolarization by high K+ induced an enhancement of the [3H]choline uptake in the presence of Ca2+. The crude synaptosomal fraction obtained from primary cultured neurons possessed approximately forty-fold higher synthesizing activity of [3H]acetylcholine from [3H]choline than that found in the homogenate preparation of cultured neurons. The present results strongly suggest that the primary cultured neurons used in this study possess a sodium- and energy-dependent high-affinity choline uptake system as well as a synthesizing system for acetylcholine. Possible usefulness of these neurons for investigating neuronal uptake of choline and its functional role in the biosynthesis of acetylcholine are also suggested.

Acetylcholine↗
PubMed1991

[Effect of careful tooth-brushing instruction by teachers on incipient gingivitis in school children].

At the Hiraizumi Primary School in Iwate Prefecture, 84 children with incipient gingivitis were selected at the annual dental examination in May. And the teachers instructed these children individually how to remove the remaining dental plaque. Moreover, the children were checked for the cleanliness of the teeth and inflammation of the gingiva by the teacher or their parents three times a day during the one week just before the second examination. In July the second examination was held and it was revealed that in sixty-three of eighty-four selected children the incipient inflammation of gingiva had improved.

Age Factors↗
PubMed1991

[A five-year follow-up study on blood pressure and serum cholesterol in junior high school children].

Blood pressure and serum cholesterol changes over a five-year period were studied in 299 junior high school children (127 males and 172 females) examined during 1980-1984 in Akita Prefecture, Japan. The six factors studied were height, weight, body mass index (by Minowa's method), systolic blood pressure, diastolic blood pressure and serum cholesterol. Mean values for systolic and diastolic blood pressure increased more than 10 mmHg during the five years in both sexes. Significant positive correlations between initial and follow-up blood pressure ('tracking') were observed. The correlation coefficients for systolic blood pressure in males and in females were 0.33 and 0.28 respectively, and those for diastolic blood pressure were 0.36 in males and 0.19 in females. While there were no significant differences in serum cholesterol levels between the two periods in either sex, the correlation coefficients, which were higher than those for blood pressure, were 0.55 in males and 0.45 in females. Among the six factors at each period, significant positive correlations were observed between height and systolic blood pressure at the initial period, and between obesity and systolic blood pressure at both periods in males and females. A significant positive relationship between obesity and serum cholesterol was seen at the follow-up period in both sexes. These data suggest that a moderate degree of 'tracking' occurs in blood pressure and serum cholesterol during childhood, and that obesity is an important factor related to blood pressure and serum cholesterol.

Adolescent↗
PubMed1990

Alterations in receptor-coupled second messenger systems at up-regulated muscarinic receptors: analysis using primary cultured neurons.

The effect of a long-term exposure (5 days) to atropine on muscarinic acetylcholine receptors and receptor-coupled second messenger systems was investigated using mouse cerebral cortical neurons in primary culture. The long-term exposure of neurons to atropine (10 nM) induced increases in both the Bmax and Kd values of [3H]quinuclidinyl benzilate (QNB) binding to muscarinic acetylcholine receptors. Alterations in muscarinic receptor-coupled second messenger systems, such as phosphoinositide (PI) hydrolysis and cyclic GMP (cGMP) formation following a long-term exposure to atropine, were also examined. Carbachol-stimulated PI hydrolysis was found to be decreased by the exposure to atropine in spite of the increase of muscarinic receptors. In addition, a long-term exposure to atropine had no effect on carbachol-stimulated cGMP formation as well as on the rightward shift of the carbachol competition curve of [3H]QNB binding in the presence of GTP. These results suggest that the up-regulation in muscarinic cholinergic receptors induced by long-term exposure to atropine may involve not only the increase in number of muscarinic receptors but also the decreased responsiveness in muscarinic receptor-coupled second messenger systems.

Animals↗
PubMed1990

Phorbol ester-induced expression of the common, low-affinity binding site for primary prostanoids in vascular smooth muscle cells.

We showed in an earlier study (Hanasaki, K., and Arita, H. (1989) Biochim. Biophys. Acta 1013, 28-35) that there is a common, low-affinity binding site for primary prostanoids in cultured vascular smooth muscle cells (VSMC). This site, called the "primary prostaglandin (PG) site," can be evaluated by radioreceptor assay using [3H]PGF2 alpha and [3H]PGE1. Comparison of the capacity of several PGF2 alpha analogs to displace both radioligand bindings indicated strict requirements of the 15-hydroxy group as well as the 13,14-double bond in the omega-side chain of prostaglandins for recognition of this site. Treatment of VSMC with phorbol 12-myristate 13-acetate (PMA), a known protein kinase C activator, led to concentration- and time-dependent increases in the binding activities of [3H] PGF2 alpha as well as [3H]PGE1, which could be completely suppressed by the addition of protein kinase C inhibitor, H-7. The PMA effects could be mimicked by phorbol 12,13-dibutylate, but not by inactive phorbol ester. Scatchard analyses revealed an approximately 8-fold increase in the binding density with unaltered binding affinity after PMA treatment. This expression of the primary PG site was blocked by the addition of cycloheximide and actinomycin D. In contrast, PMA did not affect the binding activity for the thromboxane A2/prostaglandin H2 receptor in VSMC. These results suggest that the expression of the primary PG site is regulated by a protein kinase C-dependent mechanism in VSMC.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1990

Electrical myotonia and cataract in X-linked muscular dystrophy (mdx) mouse.

An X chromosome-linked mouse mutant (mdx) has been investigated as an animal model of Duchenne's muscular dystrophy, and has been found to have the same defect of dystrophin in the muscle surface membrane. Intracellular recordings from the mdx mouse hemidiaphragm preparations revealed low resting membrane potentials and electrical myotonia which occurred at the time of microelectrode insertion and withdrawal. Electrical myotonia of the mdx mouse was observed in 30-50% of the impaled muscle fibers at low temperature, which decreased to only 7.8% at 37 degrees C. Electrical myotonia of mdx mice was not abolished by (+)-tubocurarine. Though there was no behavioral myotonia in mdx mice, repetitive bursts of action potentials in mdx mice were based on the abnormalities of the muscle membrane since neuromuscular blockade did not abolish the repetitive bursts. Also close observation of the lenses of mdx mice revealed cataracts from the newborn stage to the adult age. Slit lamp examination of the lenses of the mdx mice revealed nuclear cataracts followed by anterior subcapsular cataract as they grew. The cataract of mdx mice is different from that of myotonic dystrophy which is usually posterior subcapsular.

Animals↗
PubMed1990

A case of bilateral ptosis associated with cerebral hemispheric lesions.

Ptosis occurs in a variety of disorders including myasthenia gravis, oculomotor palsy, Horner's syndrome and brain stem disorders. There are also supranuclear lesions causing blepharoptosis. The latter disorders are reflex blepharospasm, apraxia of eyelid opening and Meige's syndrome. Since the total number of bilateral ptosis associated with cerebral hemispheric lesions is very few, whether the responsible lesions are located in the nondominant hemisphere or bilateral hemispheres are still controversial. We report here a case of bilateral cerebral ptosis that occurred in association with cerebral infarction of the nondominant hemisphere.

Aged↗
PubMed1990

The stabilizing effect of bestatin on the resting membrane potentials of X-linked muscular dystrophy mice.

The resting membrane potentials of X-linked muscular dystrophy (mdx) mice are about 10 mV lower than those of control (C57BL/10Sc) mice. Also repetitive action potentials which resemble insertion myotonia are frequently recorded intracellularly from the mdx mice of various ages. When the mdx mice are treated with bestatin intraperitoneally for 7 days, the RMP's improvement almost attained its normal levels. Repetitive action potential bursts (electrical myotonia) recorded at the time of microelectrode insertion had decreased or abolished after bestatin therapy. Another set of in vitro experiments to see direct action of bestatin to the hemidiaphragm preparations of the mdx mice reveal improvement in RMP's and a reduction in electrical myotonia within a 30-minute exposure to Tyrode's solution with bestatin. Bestatin has a favorable direct effect on the muscle fiber membrane to stabilize RMP's and suppress muscle membrane irritability.

Animals↗
PubMed1990

Prognosis and disability of stroke patients after 5 years in Akita, Japan.

The system of registering stroke patients was begun in 1963 in Ikawa Town, Akita Prefecture, Japan. The town is located in the northeastern part of the country and in 1975 had a population of 6,427. From 1975 to 1981, 109 patients who suffered their first stroke were registered and were monitored for 5 years. The average annual incidence rates of stroke were 2.8 and 2.0 per 1,000 population in males and females, respectively. Mean age at stroke onset was 63.3 and 71.4 years in males and females, respectively (p less than 0.01). According to the clinical classification of stroke, 76 patients suffered cerebral infarction, 21 cerebral bleeding, and six subarachnoid hemorrhage; six strokes were unclassified. The survival rates were compared by sex, age, and clinical stroke type using Cox's proportional hazards model. The survival rate of female stroke patients was lower than that of males, but not significantly so. The survival rate of stroke patients greater than or equal to 65 years old was significantly lower (p less than 0.01) than that of younger patients. Moreover, the survival rate of patients with cerebral bleeding was significantly lower (p less than 0.01) than that of patients with cerebral infarction. In the analysis of self-care among the survivors, performance of the activities of daily living in older patients indicated significantly less independence (p less than 0.01) in younger patients. Follow-up of new stroke cases showed that age and clinical stroke type were significantly associated with survival and that age was also related to disability of the survivors.

Activities of Daily Living↗
PubMed1990

Inhibitory effect of di- and tripeptidyl aldehydes on calpains and cathepsins.

Eight different di- and tripeptidyl aldehyde derivatives, each having at its C-terminus an aldehyde analog of L-norleucine, L-methionine, or L-phenylalanine with a preceding L-leucine residue, were synthesized and tested for their inhibitory effects on several serine and cysteine endopeptidases. These compounds showed almost no inhibition of trypsin, and only weak inhibition of alpha-chymotrypsin and cathepsin H, while they exhibited marked inhibition of cathepsin B less than calpain II congruent to calpain I less than cathepsin L, being stronger in this order. The mode of inhibition of these cysteine proteinases was competitive for the peptide substrate used and inhibitor constants (Ki) were calculated from the Dixon plot. The best inhibitors found were: 4-phenyl-butyryl-Leu-Met-H for calpain I (Ki, 36 nM) and calpain II (Ki, 50 nM); acetyl-Leu-Leu-nLeu-H for cathepsin L (Ki, 0.5 nM); acetyl-Leu-Leu-Met-H for cathepsin B (Ki, 100 nM).

Aldehydes↗
PubMed1990

[A clinical study on the changes in interocclusal contact caused by attrition, especially on the closely occluding area of upper molar region].

Changes caused by attrition in interocclusal contact were investigated in 11 subjects with natural dentition showing no or only slight attrition and 6 subjects with natural dentition showing moderate attrition. Interocclusal spaces in the molar region in the maximally intercuspidated position of each subject were recorded in White Silicone impression material. Light-transmittance measurements of interocclusal records were made to determine differences in interocclusal spaces. Results 1. Mean values of the most closely occluding area in the upper molar region Tooth kind I B II B I M II M Slight-attrition group 0.6 0.9 3.2 2.5 (mm2) Moderate-attrition group 7.2 11.0 30.4 26.8 (mm2) 2. Mean values of ratios between most closely occluding areas and occlusal-surface projecting areas in the upper molar region Tooth kind I B II B I M II M Slight-attrition group 1.1 1.7 3.1 2.7 (%) Moderate-attrition group 13.1 21.0 28.4 27.5 (%) Conclusions 1. Differences in interocclusal spaces between the slight- and moderate-attrition groups were apparent only in the most closely occluding areas. 2. When load on supporting tissues is proportionate to the size of the closely occluding area, the supporting load probably increases as attrition progresses, although the ratio of increasing load changes little among different kinds of teeth.

Dental Occlusion↗
PubMed1989

Micronucleus test with 2-acetylaminofluorene by intraperitoneal injection and oral administration.

The effect of route of administration on the outcome of the mouse micronucleus test was evaluated in 2 laboratories by administering 2-acetylaminofluorene (2-AAF) by intraperitoneal injection (i.p.) and oral gavage (p.o.) to 2 mouse strains, MS/Ae and CD-1. On the basis of a small-scale acute toxicity study and a pilot micronucleus test, the full-scale experiment was performed with a 24-h sampling time at doses ranging from 75 to 600 mg/kg by both routes. The results indicated that 2-AAF induced micronucleated polychromatic erythrocytes (MNPCEs) at all doses tested by both routes. In the MS/Ae strain, higher doses were required by p.o. than by i.p. to reach a similar level of MNPCE incidence. On the other hand, similar responses were recorded by both administration routes with CD-1 mice. Since the LD50 for the p.o. route was higher than that for the i.p. route in both strains, the route-related difference with MS/Ae mice became small when the comparison between i.p. and p.o. was made on the basis of the LD50. Thus both i.p. and p.o. routes are acceptable in the micronucleus test of this chemical.

2-Acetylaminofluorene↗
PubMed1989

[Bone inductive activity of hydroxyapatite-bone morphogenetic protein complex].

Bone morphogenetic protein (BMP) is known to be a protein which induces new bone at heterotopic sites. Purification of BMP has not been perfected, and obtaining large amounts of BMP is very difficult, so it seems better to use some carrier or frame material for BMP to work effectively. Various kinds of hydroxyapatite (HAP) have been used to repair periodontal osseous defects, but they do not have osteogenetic or osteoinductive properties. If osteoinductive proteins such as BMP could retain their biologic properties after being implanted into living tissue with HAP, it would be an advantage in repairing periodontal osseous defects. In this experiment, we prepared BMP-HAP complex and investigated its osteoinductive activity. BMP was extracted from bovine cortical bones in accordance with the Urist's procedure. The ability of this BMP to stimulate new bone growth was ensured by implantation in the muscle pouch of mice. HAP was synthesized by the wet method. The BMP-HAP complex was implanted in the muscle pouch of mice, and osteoinduction was examined 3, 7, 14, and 21 days after implantation to assess its osteo-inductive ability. New bone formation was studied by roentgenographic and histologic observation. In the BMP-HAP group, new bone formation was seen on the roentgenograms and new cartilage and bone were observed histologically in the tissue surrounding the apatite. In the HAP group, no new cartilage or bone formation was noted.

Alveolar Bone Loss↗
PubMed1989

[A development of data analyzing system for the mandibular movement].

Recent developments in medical engineering has made it easy to record biological phenomena. Furthermore, the widespread popularity of the personal computer has made data processing system remarkably efficient. In this study, an efficient personal computer system for mandibular movement analysis is investigated, and a data analyzing system for that movement developed. Applying this system to chewing movements in a small number of cases made possible efficient, easy and accurate analysis. The following is an outline of the system and its applicability. 1. Standard measuring coordinate system for mandibular position and designation of mandibular position measuring point An orthogonal coordinate system is used to the standard measuring coordinate system for mandibular position measurement coordinates. The X axis of this orthogonal coordinate system is determined as a straight line connecting two LEDs. The origin point is designated as the center between two LEDs. This connects with the upper dentition or the maxilla. The mandibular position measuring point is designated on the orthogonal coordinate system. The X axis of this orthogonal coordinate system is determined as a straight line connecting two LEDs. The origin point is designated as the center between two LEDs. This connects with the lower dentition or the mandible. The analysis of mandibular position of designated measuring point on the lower dentition or the mandible is performed corresponding to the orthogonal coordinate system on the upper dentition or the maxilla. 2. Calculation of coordinates value [mm] for mandibular position measuring point In the analysis, value [V] for the distance between two LEDs established on the upper jaw is substituted for the already input real distance [mm] between two LEDs. The coordinates value of the mandibular position measuring point is calculated from these substitution value. 3. Data recording Data concerning mandibular movement and myoelectric discharges are recorded by means of a data recorder. Digital data are converted to analogue data from the data recorder by means of a 12-bit A/D converter and they are accumulated in the memory of the personal computer system. Digital data in the memory of the personal computer system can be stored in about 97 seconds for the storage capacity of a floppy disk (2HD) memory area.

Data Interpretation, Statistical↗
PubMed1989

Partial purification and characterization of alpha-glucosidase from Rothia dentocariosa.

Disaccharidases of oral bacteria, especially alpha-glucosidase and beta-fructofuranosidase, are considered to play an important role in the induction of dental caries. Upon the examination of disaccharidases from several strains of saccharolytic oral bacteria, we found all of those bacteria to be capable of hydrolyzing the glycosidic linkage of sucrose. One species of bacteria, Rothia dentocariosa, was found to contain a single disaccharidase, alpha-glucosidase. This enzyme was partially purified by ammonium sulfate precipitation, gel filtration and ion-exchange column chromatography. The optimum pH and temperature for the enzyme activity was found to be 6.8-7.0 and 40 degrees C, respectively. The enzyme activity was strongly inhibited by Ag+, Hg2+, Cu2+, Fe2+ and Tris (Hydroxymethyl) aminomethane.

Bacteria↗
PubMed1989

[Pharmacokinetics of arbekacin in healthy volunteers and patients with renal insufficiency].

Pharmacokinetics of arbekacin (HBK), a new aminoglycoside, was studied. Serum concentrations and urinary excretion were determined after single intravenous drip infusion of 100 mg HBK for 1 hour to healthy volunteers and patients with renal insufficiency of various kinds. The drug concentration was determined with bioassay, fluorescence polarization immunoassay (FPIA) and high-performance liquid chromatography (HPLC). Pharmacokinetic analysis was made in accordance with the two-compartment open model, and 24-hour endogenous creatinine clearance (Ccr) was used as the renal function index. In all cases peak serum levels were detected 1 hour after administration, and similar values were noted regardless of subjects' proficiencies of renal function. However, the serum clearance during beta-phase tended to be prolonged parallel with the degree of renal insufficiency. The excretion of HBK into urine was prolonged and cumulative recovery tended to be decreased in association with the decreased valued of Ccr.

Adult↗