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Y Kohno

Publications and source records attributed to Y Kohno.

At least 343 records · Page 19Linked to original sources
PubMed1981

[Effect of L-DOPA on brain serotonin metabolism related to tryptophan concentrations in plasma and brain of rats].

Changes in tryptophan (Trp) concentrations in the peripheral and brain tissues and their influences on brain serotonin (5-HT) metabolism were investigated after i.p. administrations of L-DOPA alone and in combination with Ro4-4602 in male Wistar rats. L-DOPA alone elicited marked increases of both plasma free and liver Trp levels, and a slight increase of brain Trp level. Concomitant application of L-DOPA and Ro4-4602 did not change peripheral Trp concentrations but did reduce brain Trp level. Brain 5-HT levels were reduced in proportion to the increase of dopamine (DA) level by L-DOPA alone and Ro4-4602 plus L-DOPA. A marked increase of 5-HIAA level was exhibited by L-DOPA alone, while Ro4-4602 plus L-DOPA increased 5-HIAA levels slightly despite a marked decrease in 5-HT levels. The decrease of 5-HT and increase of 5-HIAA levels were also observed after administration of L-DOPA to neonatal rats in which the brain tryptophan hydroxylase was considered to be saturated. These results suggest that changes in 5-HT metabolism after L-DOPA injections are not only caused by DA which displaces 5-HT from vesicular stores, but also by changes in Trp concentrations in the plasma and brain which alter 5-HT synthesis and turnover.

Animals↗
PubMed1979

Brain serotonin metabolism with relation to the head twitches elicited by lithium in combination with reserpine in mice.

Lithium alone, which scarcely induced head twitches, did not affect brain 5-hydroxytryptamine (5-HT) levels but increased 5-hydroxyindoleacetic acid (5-HIAA) levels. However, the combined use of lithium chloride (2 mEq/kg x 5, SC) and reserpine (5 mg/kg, SC) administered hourly markedly elicited the head twitches, together with the pronounced decrease of 5-HT levels and increase of 5-HIAA levels as similarly seen by reserpine alone. Pretreatment with p-chlorophenylalanine (PCPA) strongly potentiated the twitches elicited by the combined administration of lithium and reserpine, along with inducing the significant decrease of 5-HT levels and no change of 5-HIAA levels as compared with those levels in the PCPA-treated mice. The results imply that lithium produces the head twitches in the presence of reserpine, and an increase of 5-HIAA or a decrease of 5-HT levels do not necessarily interfere with the incidence of the twitches, and that the receptor sensitivity to 5-HT is strongly involved in the incidence of the head twitches.

Animals↗
PubMed1976

Selective depleting effect of syrosingopine on brain catecholamine levels with relation to morphine analgesia in the rat.

Reserpine was the most potent, rescinnamine the next and syrosingopine the weakest in the depleting effects on brain amines of rauwolfia alkaloids. After syrosingopine, brain dopamine (DA) was decreased to a smaller degree and with a shorter duration as compared with norepinephrine (NE) and serotonin (5-HT), whereas reserpine elicited a marked and long lasting reduction in these amines. Accordingly, syrosingopine induced a depletion of brain NE and 5-HT without alteration in brain DA content 2-4 days after administration. Repeated administrations of syrosingopine, 2 mg/kg daily for 2 or 4 days, resulted in similar alterations in brain amine levels. This selective depleting effect of syrosingopine on brain amines was potentiated by combined treatment with disulfiram or fusaric acid, a dopamine beta-hydroxylase inhibitor. Under the condition of selective depletion of brain amines induced by repeated administrations of syrosingopine, 2 mg/kg daily for 2 days, the analgesic action of morphine was not affected, whereas reserpine and tetrabenazine antagonized morphine analgesia, concomitant with inducing a depletion of all brain amines. The results suggest that brain DA may be more important than brain NE or 5-HT with regard to the mechanisms by which morpine produces analgesia.

Analgesia↗
PubMed1976

Characteristics of biliary excretion of cefazolin and other cephalosporins with reference to the relationship between serum levels and administration conditions.

The biliary excretion of cefazolin was compared with that of cephalothin and cephaloridine in rats and man. In rats, the biliary levels were dose-related with cefazolin and cephalothin but not with cephaloridine. Biliary levels were higher than serum levels after injection of 10--80 mg/kg of cefazolin and cephalothin, whereas serum levels of cephaloridine after injection were higher than biliary levels. The highest biliary levels of cefazolin were obtained by intravenous injection, followed by intramuscular injection and drip infusion. In man, a crossover study was made to compare biliary levels of cefazolin with those of cephaloridine and cephalothin. After a single 1-gram intravenous injection, the peak levels of cefazolin ranged from 0.85 to 21 mug/ml and those of cephaloridine varied from 0.55 to 3.9 mug/ml. After a 3-gram intravenous injection, the peak biliary levels of cefazolin ranged from 35.5 to 270 mug/ml and those of cephalothin from 0.3 to 64 mug/ml. The chemotherapeutic biliary levels of cefazolin able to inhibit susceptible organisms were obtained by 3-gram intravenous injections.

Animals↗
PubMedDate not supplied

Non-radioactive DNA diagnosis for the fragile X syndrome in mentally retarded Japanese males.

A rapid screening test was developed to detect CGG repeat expansion of the FMR-1 gene causing the fragile X syndrome by a non-radioisotope PCR technique. A biotin-labeled primer was initially used and the biotin-labeled PCR product was detected by means of chemiluminescence. The normal PCR product of around 300 bp was not created in the abnormal FMR-1 gene sample with this method. Four positive samples were found among those from 226 mentally retarded males, but the CGG repeat expansion was shown on Southern blot analysis in only one sample. To eliminate false-positive samples, a hybridization method involving a biotin-labeled (CGG)s oligonucleotide was developed for the PCR product and the CGG repeat expansion could be detected. Finally, 256 mentally retarded males in Japan were examined and only 2 abnormal samples were detected. The prevalence of this abnormality was less than 1%, which is relatively lower than those reported previously.

Base Sequence↗
PubMedDate not supplied

Pure motor monoparesis of a lower limb due to a small infarction in the contralateral motor cortex.

Pure motor monoparesis (PMM) is a rare condition characterized by weakness limited to one limb without sensory disturbance. We report a 42-year-old woman with PMM of the right lower limb caused by a small infarction in the contralateral motor cortex that could be detected by the magnetic resonance imaging of the brain. This case suggests that small lesions, missed by carelessly performed scans, could be a potential cause of PMM. This is especially true in the case of lower limb PMM, because the lesion may be located in the top of the frontal lobe cortex, an area that can be easily missed by routine scans. Therefore, we should pay careful attention to the opposite side of the motor cortex in examining neuroimages of PMM cases.

Adult↗
PubMedDate not supplied

Homing receptor expression on cord blood T lymphocytes and the development of atopic eczema in infants.

Expression of the gut-homing receptor integrin alphaEbeta7, but not cutaneous lymphocyte-associated antigen (CLA), on milk allergen-stimulated cord blood T lymphocytes precedes the development of milk-induced eczema in early infancy. The data indicate the involvement of integrin alphaEbeta7 in the development of infantile allergic eczema and provide a clue to the avoidance of specific allergens and novel therapy targeting homing receptors in food allergy.

Allergens↗
PubMedDate not supplied

Step-down and step-up therapy in moderate persistent asthma.

BACKGROUND: A step-down therapy may be more beneficial for the management of asthma than a step-up therapy. METHODS: Eighty-two asthmatic patients with moderate persistent asthma were enrolled in the study and randomized into three groups. One group of patients received 400 microg/day of beclomethasone dipropionate (BDP) for 4 weeks and then 800 microg/day for another 4 weeks (step-up group). The other two groups of patients received 1,200 microg/day of BDP for 4 weeks with or without short-term oral steroid (prednisolone, 0.5 mg/day for 1 week) and then 800 microg/day for another 4 weeks (step-down group). Severe exacerbation of asthma, asthma symptoms, respiratory function and rescue use of inhaled beta(2)-agonists were monitored. If asthma was well controlled, the dose of BDP was decreased every 3 months and if asthma was exacerbated, the dose of BDP was increased until 8 months after the initial treatment. RESULTS: Twenty-two patients during the run-in period, 4 patients in the step-up group, 2 patients in the step-down group treated with a high dose of BDP and no patients in the step-down group with oral steroids during first 4 weeks dropped out because of severe exacerbation of asthma. Although asthma symptoms and respiratory function significantly improved 8 weeks after the therapy in all groups, more significant and prompt improvements of these parameters were observed in patients of the step-down group than in patients of the step-up group after the first 2 weeks of treatment. Furthermore, step-down therapy with short-term oral steroid resulted in the lowest maintenance doses of BDP at 8 months of the three groups. CONCLUSIONS: These results suggest that step-down therapy starting with a high dose of inhaled steroid and short-term oral steroid is more effective in gaining prompt control of asthma and reducing the severe exacerbation of asthma and the maintenance dose of inhaled steroids than a step-up therapy starting with a low dose of inhaled steroids in patients with moderate persistent asthma.

Administration, Inhalation↗
PubMedDate not supplied

Partial midline fusion of the cerebellar hemispheres with vertical folia: a new cerebellar malformation?

MR imaging depicted vertically oriented folia instead of the normal horizontal folial pattern, hypoplastic cerebellar vermis, fusion of the inferior posterior cerebellum, and probable polymicrogyria in the superior cerebellar hemispheres in a child with hypotonia, nystagmus, ataxia, and psychomotor retardation. We propose that this newly discovered cerebellar malformation be added to the list of malformations associated with aplasia or hypoplasia of the cerebellar vermis, such as Dandy-Walker malformation, Joubert syndrome, tectocerebellar dysraphia, and rhombencephalosynapsis.

Ataxia↗