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Biomedical subjects

K Iinuma

Publications and source records attributed to K Iinuma.

At least 127 records · Page 7Linked to original sources
PubMed1993

Proconvulsive effects of histamine H1-antagonists on electrically-induced seizure in developing mice.

The purpose of this study was to investigate the developmental differences in seizure susceptibility in mice and the roles of the histaminergic neuron system in inhibition of convulsions in development. First, we studied developmental differences in electrically-induced seizures. Since the 14-day-old mice showed a different seizure pattern from that of older mice, we evaluated the seizure susceptibility of mice older than 21 days. The durations of all the convulsive phases were significantly increased in 21- and 30-day-old mice, compared with older mice. Second, pyrilamine (or mepyramine), ketotifen, and d-chlorpheniramine, centrally-acting H1-antagonists, increased the durations of all the convulsive phases in the 21- and 30-day-old mice, but did not increase duration in 42-day-old mice. Terfenadine and astemizole, H1-antagonists that hardly enter the brain, did not affect the durations of all the convulsive phases in 21-, 30- and 42-day-old mice. The proconvulsant effect of centrally-acting H1-antagonists in 21- and 30-day-old mice were considered to be mediated via the central H1-receptors. Thus, the histaminergic neuron system may have an important physiological role in inhibition of seizures in 21- and 30-day-old mice which have higher seizure susceptibility. This would compensate for the immaturity of the other protective neuron systems such as NMDA receptor complexes and GABA receptors. In conclusion, the present findings support the view that the central histaminergic system plays a role in inhibition of convulsions.

Aging↗
PubMed1993

Visual influence on center of contact pressure in advanced Parkinson's disease.

The visual influence on upright posture was studied in seven patients with Parkinson's disease (PD), Yahr stage III to IV, and seven age-matched controls. The position of the center of contact pressure (CCP) between the feet and floor was analyzed by a photoelastic method. When the patients' eyes were closed, the CCP position shifted significantly backward in PD (open, 48.6 +/- 7.6%; closed, 45.0 +/- 4.8%; p < 0.01), whereas in controls, it shifted significantly forward (open, 45.5 +/- 5.8%; closed, 48.9 +/- 2.8%; p < 0.05). PD patients put their body weight less on the more affected foot (open, 49.6 +/- 4.5%; closed, 47.0 +/- 4.8%; p < 0.01) and more on the less affected foot (open, 50.4 +/- 4.5%; closed, 53.0 +/- 4.8%; p < 0.005), when the eyes were closed. Visual information is important in maintaining the upright posture in PD patients.

Aged↗
PubMed1993

Proconvulsant effect of ketotifen, a histamine H1 antagonist, confirmed by the use of d-chlorpheniramine with monitoring electroencephalography.

Ketotifen produced seizures in a 5-year-old boy with secondary generalized epilepsy (SGE) and allergic rhinitis. To confirm that the seizures were due to histamine H1 receptors blockade, d-chlorpheniramine was administered with monitoring electroencephalography (EEG). Administration of d-chlorpheniramine significantly increased the number of epileptic discharges in the patient, compared with those before administration. Plasma noradrenaline and dopamine levels were not affected by treatment with d-chlorpheniramine. These findings indicate that histamine H1 receptors blockade produced convulsions and increased epileptic discharges on EEG. Recently, several experimental reports have shown that histamine has an inhibitory role on convulsions through histamine H1 receptors. Experimental findings and present results show that histamine H1 antagonists have proconvulsant effects, especially in the developmental period. Thus, it is recommended that centrally-acting histamine H1 antagonists should be avoided in epileptic patients, especially in children of pre-school age.

Child, Preschool↗
PubMed1993

MK-801 and dopaminergic system in electrically-induced convulsions in mice.

In this study, the effects of MK-801 and selective dopaminergic agents on electrically-induced convulsions in mice were examined. MK-801 (0.004-0.1 mg/kg, ip) showed significant and dose-dependent anticonvulsive effects, and the anticonvulsive effects of MK-801 (0.02 mg/kg, ip) were not antagonized by dopamine selective antagonists, SCH-23390 (D1, 0.1 mg/kg, sc), sulpiride (D2, 100 mg/kg, sc) and pimozide (D2, 0.5 mg/kg, sc). Apomorphine (0.02-0.5 mg/kg, sc), a D1/D2 agonist, showed proconvulsant effect on electrically-induced convulsions. Dopamine selective antagonists, SCH-23390 (0.02-0.5 mg/kg, sc), sulpiride (5-100 mg/kg, sc) and pimozide (0.1-2.5 mg/kg, ip), also showed proconvulsant effect. However, these effects of dopamine agonist and antagonists were not dose-dependent. These findings suggest that the dopaminergic system neither plays an inhibitory role, at least on electrically-induced convulsions in mice, nor contributes to the anticonvulsant effect of MK-801 in electrically-induced convulsions.

Animals↗
PubMed1993

[Long-term prognosis of idiopathic thrombocytopenic purpura treated by partial splenic embolization].

The therapeutic effect of partial splenic embolization (PSE) was evaluated in 13 patients with idiopathic thrombocytopenic purpura (ITP). Eight patients were treated by PSE and followed up over 6 months after the treatment. Two patients were treated by splenectomy following PSE. (1) PSE achieved complete remission in one case, partial response in 3 cases, minimal response in one case and no change in 3 cases. PSE resulted in 62.5% of the effective rate. (2) The effect of PSE did not depend on age, sex, the duration of disease, platelet count and PA-IgG level before the treatment and the splenic infarcted rate. The platelet count after PSE increased more remarkably in the effective cases than in the non-effective ones (p < 0.01), which could predict the prognosis after PSE. (3) One patient whose platelet count increased enough after PSE had splenectomy later and resulted in complete remission. However another patient whose platelet count did not increase enough after PSE revealed no effect by splenectomy. PSE for the treatment of ITP could prevent some patients from non-effective splenectomy and achieve the same effective rate as splenectomy. Therefore, PSE could be an alternative therapy of splenectomy because of the less invasive one.

Adolescent↗
PubMed1992

Opioid mu-deficient CXBK mouse and the role of mu 1-receptors in electrically induced convulsions.

Studies were made on the role of mu 1-receptors on electrically induced convulsions in mice. A relatively selective mu 1-agonist, DAGO ([D-Ala2-N-methyl-Phe4-Gly-ol]-enkephalin) decreased the durations of tonic and clonic convulsions in C57BL/6 mice, but not in opioid mu-deficient CXBK mice, indicating that the activation of mu 1-receptors had an anticonvulsive effect on these convulsions in mice. The selective mu 1-antagonists naloxonazine and naltrexonazine promoted the clonic phase of electrically induced convulsion in C57BL/6 mice. Moreover, the duration of the clonic phase was longer in mu-deficient CXBK mice than in C57BL/6 mice. These data for CXBK mice confirmed, at least some proconvulsant effects of mu 1-antagonists in C57BL/6 mice. Thus, blockade of mu 1-receptors has a proconvulsant effect, and mu 1-receptors have at least some protective role against electrically induced convulsions.

Animals↗
PubMed1992

Cell shape change and cytosolic Ca2+ in human umbilical-vein endothelial cells stimulated with thrombin.

We quantified thrombin-induced endothelial cells shape change and investigated the role of Ca2+ in such shape change. We used the fluorescent Ca2+ indicator, fura2, to measure both shape change as cell size and intracellular free Ca2+ ([Ca2+]i), in cultured human umbilical-vein endothelial cells (HUVEC). Thrombin induced concentration-dependent decreases in cell size (percentage of cell size at 6 min after stimulation with 0.01 U/ml, 0.1 U/ml, or 1 U/ml thrombin) was 90.1 +/- 1.5%, 78.1 +/- 2.4%, and 40.9 +/- 2.4%, respectively. Thrombin also increased [Ca2+]i in a concentration-dependent manner. Both depletion of extracellular Ca2+, and also the addition of W5, a calmodulin antagonist, inhibited thrombin-induced size reduction. These results indicate an association between shape change and [Ca2+]i mobilization in human endothelial cells stimulated by thrombin.

Calcium↗
PubMed1992

Histamine levels and clonic convulsions of electrically-induced seizure in mice: the effects of alpha-fluoromethylhistidine and metoprine.

The purpose of this study was to investigate the possible role of the central histaminergic neuron system in electrically-induced seizure in mice. For this purpose, we examined the effects of intraperitoneal (i.p.) injections of histaminergic agents, such as L-histidine, metoprine, and alpha-fluoromethylhistidine (FMH), on electrically-induced seizure. L-Histidine decreased the duration of clonic convulsion in electrically-induced seizure, but not affected that of tonic convulsion. This effect of L-histidine was antagonized by pretreatment with FMH, indicating that it was due to histamine formed by decarboxylation of L-histidine in the central nervous system. The anticonvulsive effect of L-histidine was also reduced by the H1-antagonist pyrilamine, but not by the H2-antagonist zolantidine, indicating that the effect on electrically-induced seizure is mediated through central H1-receptors. Metoprine, which increased the histamine levels in the cerebral cortex, diencephalon and midbrain of mice, decreased the duration of clonic convulsions dose-dependently. Conversely, FMH, which decreased the brain histamine levels, increased the duration of clonic convulsions. Good inverse correlations were found between the duration of clonic convulsions and brain histamine levels, especially in the diencephalon: the histamine levels were inversely proportional to the duration of clonic convulsions. No correlation was found between the duration of tonic convulsions and brain histamine levels. These results suggest that the histaminergic neuron system is important in inhibition of the duration of clonic convulsion on electrically induced seizure in mice.

Animals↗
PubMed1991

Dystrophin immunohistochemistry in a symptomatic carrier of Becker muscular dystrophy.

Immunohistochemical localization of dystrophin was studied in a symptomatic carrier of Becker muscular dystrophy (BMD). Muscle biopsy specimens from a female carrier showed findings compatible with slowly progressive muscular dystrophy by ordinary histochemical examinations. Immunohistochemical study, using an antiserum raised against a synthetic peptide fragment of dystrophin, demonstrated a mixture of staining patterns, including continuous but faint positive fibres, partially disrupted fibres and negative fibres. These findings were identical to those of patients with BMD and appear to differ from previous findings in female carriers of Duchenne muscular dystrophy. This report is the first immunohistochemical study of a symptomatic female proven by molecular genetic analysis to be a carrier of BMD.

Adult↗
PubMed1991

Risk determination in cases with an extra minute chromosome: prenatal diagnosis.

The interpretation of an extra minute chromosome (EMC) detected in utero presents both diagnostic and prognostic problems. Two EMC cases are presented and a flow-chart guideline is proposed for the determination of developmental risk. A prenatally detected EMC was familially inherited through a normal phenotype father. The pregnancy was continued and a normal baby boy was delivered. At one year his development was within normal ranges. The second EMC case was a mentally retarded girl examined at 4 years and 7 months of age. The EMC was identified with a combination of various staining techniques to be an inversion duplication (15). The importance of differential diagnosis of EMCs by DA/DAPI staining is emphasized.

Adult↗
PubMed1991

[Enhancement of selective drug accumulation and retention in normal and regenerating liver by the use of lipiodol in portal venous infusion in rats].

We studied selective accumulation and retention of lipiodol (LP) and anticancer agents in normal and regenerating liver tissue following portal infusion in rats. Total concentration of Aclarubicin (ACR) and its metabolites in liver tissue was higher in ACR + LP portal infusion group than in ACR portal infusion group both in normal and regenerating liver, concentration of active metabolites of ACR was higher in ACR portal infusion group than in ACR peripheral infusion group. Much higher concentration was found in ACR + LP portal infusion group. Histologic examination revealed more toxic effect on regenerating liver in ACR portal infusion group than in ACR + LP portal infusion group. Oil red staining demonstrated the retention of lipiodol more than 7 days following intraportal infusion in regenerating liver tissue. This study confirms that the ACR + LP portal infusion induces selective accumulation and long-term retention in normal and regenerating liver tissue, and may enhance the antitumor effect of drugs.

Aclarubicin↗
PubMed1991

[Photoelasticity study of feet in Down syndrome].

Developmental studies of postural regulations have contributed to a field of developmental neurology, and one of the most efficient approaches may be a measurement of plantar contact pressure patterns. In the present study, a photoelasticity technique which can visualize the loading force as isochromatic circle patterns was used as a "sensor" part for quantification of plantar pressure. Children with Down syndrome (DS) (n = 18) known to have marked muscular hypotonicity were examined as a clinical model for functional evaluation of plantar arches in respect to body-weight-loading distribution. The results showed that the first fringe number in DS is significantly increased and Cv value for the local force supporting the body weight of DS children is significantly decreased. This type of analytical method proves to be useful for objective evaluation of musculo-skeletal functions of feet under the condition of standing upright at rest.

Body Weight↗
PubMed1991

[Photoelastic studies of the position of plantar pressure center and its changes at standing upright: analysis on Down syndrome].

With a photoelastic method, contact pressure patterns between foot and the floor surface were recorded, occasionally for one minute. The aim of this study is to evaluate the development or maturity of postural control. As a clinical model to be tested, Down syndrome characterized by marked muscular hypotonicity was chosen for quantitative analysis. The following results were obtained; (1) the center of contact pressure is shifted significantly forward in Down syndrome, (2) the position tends to move forward on the left side in both normal and Down syndrome groups, and (3) there was no distinctive laterality of weight loading on either side. Flaccidity of ankle joint movements such as abnormal eversion was indicated by a special parameter, which was obtained for the first time by this method.

Child↗
PubMed1991

[Hepatic functional evaluation using the galactose tolerance test in patients with obstructive jaundice].

Hepatic functional mass was evaluated in patients with obstructive jaundice using the galactose tolerance test (GaTT), which reflected cytosolic function of hepatocyte. The T-1/2 values as an index on the GaTT were significantly prolonged in patients with obstructive jaundice in comparison with control subjects whether before or after percutaneous transhepatic biliary drainage (PTBD). But in each cases, some showed nearly normal GaTT-T/2 value and others showed severely prolonged value. Patients with obstructive jaundice could be divided into two groups according to the GaTT-T/2 value before PTBD. The decreasing rate of serum bilirubin level "b" after PTBD was significantly fair in the group A patients (good GaTT-T/2 value before PTBD) than the group B (poor GaTT-T/2 value before PTBD) (P less than 0.05). It was that GaTT-T/2 before PTBD which represented hepatic cytosolic functional mass could predict the effect of PTBD in patients with obstructive jaundice.

Aged↗
PubMed1990

Mosaicism of mitochondria in mitochondrial myopathy: an electronmicroscopic analysis of cytochrome c oxidase.

Electron microscopic histochemistry was applied to the study of cytochrome c oxidase activity in each mitochondrion of biopsied muscles from four patients with mitochondrial myopathy [one case of fatal infantile mitochondrial myopathy, one case of myoclonus epilepsy associated with ragged-red fibers (MERRF), and two cases of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS)]. In the patient with fatal infantile mitochondrial myopathy, intercellular heterogeneity of mitochondria was recognized. In the three patients with either MERRF or MELAS, cytochrome c oxidase activity was segmentally changed from positive to negative within single muscle fibers. In the two patients with MELAS, small groups of positive-stained mitochondria were located among negative-stained mitochondria in the negative segment of a few muscle fibers. These findings revealed that there were heterogeneous populations of normal and abnormal mitochondria intracellularly or intercellularly within the muscles of these patients.

Adult↗
PubMed1990

An evaluation of an in vivo local sound speed estimation technique by the crossed beam method.

An in vivo local sound speed estimation technique, using the crossed beam method, has been proposed and its applicability was evaluated. At first, the potential of this technique was studied by a mapping simulation using the ray tracing technique followed by an experiment with a cylindrical agar phantom. The simulation result showed that an exact measurement of local sound speed values was difficult, but the sound speed information for the local region (its relative magnitude to the surrounding medium) was emphasized as a refraction mapping pattern. The experimental results agreed well with the calculation results. Furthermore, a clinical application was performed, using the clinical system (modified electronic linear scanner), on two liver tumor patients.

Acoustics↗