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Biomedical subjects

K Kurata

Publications and source records attributed to K Kurata.

At least 91 records · Page 5Linked to original sources
PubMed1993

Premotor cortex of monkeys: set- and movement-related activity reflecting amplitude and direction of wrist movements.

1. Neuronal activity was recorded from the premotor cortex (PM) of Japanese monkeys while they performed hand movements with different amplitudes and directions. On each behavioral trial, two instructions were given sequentially: 1) an amplitude instruction (large or small) and 2) a direction instruction (flexion or extension). The onset of movement was triggered by a visual signal after a delay period. 2. Among various kinds of task-related neuronal activity recorded in the PM, two types were selected for study: 1) set-related activity, sustained activity change during the delay period that followed presentation of instruction signals (IS); and 2) movement-related activity, activity change immediately before and during movement, which followed the trigger signal (TS) presentation. 3. Thirty-two of 101 set-related neurons showed activity change after presentation of the first IS (Delay 1 set-related activity), when they were instructed in either amplitude or direction, but not both. All of the set-related neurons showed activity modulation after presentation of the second IS (Delay 2 set-related activity). When neurons showed both Delay 1 and Delay 2 set-related activity, they were usually more active during Delay 2, i.e., when the monkeys had received both amplitude and directional ISs. A majority of neurons with Delay 2 set-related activity (64%) showed relation to both movement amplitude and direction. Twenty-eight percent of the neurons showed relation to either amplitude or direction, but not both. These findings seem consistent with a view that serial, rather than parallel, processes of motor programming operate in preparation of intended movements. 4. A majority of PM neurons with movement-related activity (51%) showed activity change related to both the direction and amplitude of movement. Forty-two percent showed selective relation to either direction or amplitude. These findings support a view that PM contributes to the control of limb movements. 5. Histological reconstruction showed that a vast majority of PM set-related neurons were located in the dorsal aspect of the PM (PMd), medial to the arcuate spur and lateral to the superior precentral sulcus. In contrast, movement-related neurons were distributed in two distinct foci: one in the ventral aspect of the PM (PMv), immediately caudal to the genu of the arcuate sulcus and lateral to the spur of the sulcus; and the other in the PMd, overlap;ing the location of set-related neurons.(ABSTRACT TRUNCATED AT 400 WORDS)

Afferent Pathways↗
PubMed1993

Compliance of the patulous eustachian tube.

The compliance and ventilatory functions of the eustachian tube (ET) of 17 ears with patulous ETs were examined and compared to those of 16 ears with traumatic perforation of the eardrum (controls) by means of the tubal compliance test, the inflation-deflation test, and the forced response test. The tubal compliance was significantly lower in the patulous ETs than in the controls. An excessive patency of the ET was confirmed among the patients with patulous ETs by a low opening pressure during the inflation test and a low passive resistance on the forced response test. Active ventilatory dysfunction was also found to be significantly more common in the patulous ETs by the deflation test and the measure of dilation efficiency. These results indicated that the ET appeared to be rather rigid and less moveable when patulous than when normal.

Adult↗
PubMed1993

Eustachian tube compliance in sniff-induced otitis media with effusion. A preliminary study.

Compliance and ventilatory functions of the eustachian tube (ET) were examined in 20 ears with sniff-induced otitis media with effusion (OME) and 16 ears with traumatic perforation of the eardrum (control) by the forced response test (FRT) including the compliance test, and by the inflation-deflation test. The tubal compliance showed no significant difference between two groups in the FRT. The inflation test revealed that the forced opening pressure was significantly lower in the sniff-induced OME group than in the controls. In the FRT, the active ventilatory dysfunction was also revealed to be significantly more common in the sniff-induced OME. These results suggested that most of the ETs with sniff-induced OME seemed to have excessive patency and poor active opening ability, but may not be hypercompliant or "floppy".

Adolescent↗
PubMed1993

[Investigation of meropenem levels in the human bone marrow blood, bone, joint fluid and joint tissues].

A solution of 0.5 g of meropenem (MEPM) in 100 ml of saline was administered to adult patients before the orthopaedic surgery via intravenous drip infusion for 30 minutes. Eleven samples of bone marrow blood, 13 bone, 8 joint fluid and 8 joint tissues obtained from 15 clinical cases were analyzed for MEPM levels. At the same time, blood samples were taken from peripheral veins and serum served as control was analyzed. The concentration of MEPM in the marrow blood at 30 minutes after administration of MEPM reached 15.4 micrograms/ml, which was above 50% of the maximum concentration in serum. Ratios of concentration in bone marrow to that in serum were between 93% and 105% at that time. MEPM levels were 5.74-0.40 micrograms/g in bones, 20.3-4.55 micrograms/ml in joint fluid and 18.2-4.05 micrograms/g in joint tissues at 30 to 75 minutes after administration. In joint fluid and joint tissues, the concentration above 50% of maximum level in serum were maintained for more than an hour. MEPM is thought to be useful for the treatment of bone and joint infections and also prophylaxis of infections in cases of major surgery of skeletal tissue in the field of orthopaedic surgery.

Adult↗
PubMed1993

[The cranial MRI in severe cerebral palsy: a comparative study with clinical data].

The magnetic resonance examination was performed in 38 patients with severe cerebral palsy (CP; 15 males and 23 females) who had both motor delay (unable to move anywhere) and mental retardation (I. Q or D. Q below 30). Neuroimaging findings were compared with the CP type, etiology, and grade of understanding of language. Cranial magnetic resonance imagings (MRI) in CP were divided into five types. Type 1 : nine predominantly showed cyst-liked ventricles and periventricular hyperintensity on T2-weighted imaging (PVH) and only scarred basal ganglia and thalamus were visible. All suffered from neonatal asphyxia and the clinical type was rigospastic tetraplegia (RST). Type 2: eleven predominantly showed PVH and hyperintensity on T2-weighted (HT2) in basal ganglia and thalamus. All suffered from neonatal asphyxia and the clinical type was RST or rigospastic diplegia. Type 3: five showed PVH and three had cortical atrophy. All suffered from neonatal asphyxia and the clinical type was spastic diplegia. Type 4: four predominantly showed HT 2 in putamen and thalamus. Three had cortical atrophy. All suffered from neonatal asphyxia. The clinical type was athetotic CP (ATH). Type 5: nine predominantly showed HT 2 in globus pallidus. Four had cortical atrophy and two had hippocampal atrophy. All suffered from neonatal jaundice and the clinical type was ATH. All patients who suffered from neonatal asphyxia and spastic CP had MRI in PVH. All patients who suffered from neonatal asphyxia and ATH showed HT 2 in putamen and thalamus. Almost patients who suffered neonatal jaundice and ATH showed HT 2 in globus pallidus. With athetotic CP, cases with atrophy of the cerebral cortex or/and hippocampus were lower grade of understanding of language than no atrophy of both. The result of studies of MRI are in agreement with neuropathological findings.

Adolescent↗
PubMed1993

[Long-term clinical course of sequelae in patients with neonatal anoxic encephalopathy resulting in profound mental retardation and motor disturbance].

A long-term observation has been made in 58 patients (30 males and 28 females) with severe sequelae of neonatal anoxic encephalopathy. They aged from 8 months to 65 years. All of them had motor disturbances and profound mental retardation. Motor function was improved in 4 patients with aging. In contrast, motor activity deteriorated in 11 cases, of which 4 showed a mental regression. Among them, patients who had originally better motor ability than sitting were likely to deteriorate by uncontrollable epilepsy and/or excessive administration of anticonvulsants. Regression of the patients with worse motor ability like bedridden appeared to attributable hypertonia of muscles and bodily deformation. Fifteen cases showed an exacerbation of general condition which originated predominantly to respiratory distress. Twelve patients died including 6 exacerbated cases. Exacerbation or death may have occurred frequently in specific periods of infancy, adolescence and youth with the patients who showed very low motor function such as bedridden and no locomotion.

Adolescent↗
PubMed1993

Effects of dietary vitamin E on clinical course and plasma glutamic oxaloacetic transaminase and glutamic pyruvic transaminase activities in hereditary hepatitis of LEC rats.

Long-Evans Cinnamon (LEC) rats are autosomal recessive mutants that develop hepatitis and hepatocellular carcinoma. Because copper accumulates in the livers of these rats, and some of their clinical and pathological features are similar to those of patients with Wilson's disease, LEC rats are proposed as an animal model of Wilson's disease. It has been thought that unbound copper generates free radicals, which act as hemolytic and hepatocytotoxic agents. To examine the effects of vitamin E as an antioxidant on hereditary hepatitis in LEC rats, we fed 3-week-old rats for 25 weeks either vitamin E-deficient, control, or vitamin E-supplemented diets which contained < 0.01 mg of total tocopherols, 2 mg of d,l-alpha-tocopheryl acetate (2 I.U.), and 58.5 mg of d,l-alpha-tocopheryl nicotinate (50 I.U.), respectively, per 100 mg of feed. In males, body weight loss was first observed in the vitamin E-deficient group, and mean ages at which jaundice occurred were in the order: deficient younger than control younger than supplemented groups. The ages when plasma glutamic oxaloacetic transaminase and glutamic pyruvic transaminase activities began to increase sharply and peaked followed the same order. Thus, it is likely that free radicals are involved in jaundice and hepatitis in LEC male rats, and they are a model for studying the relationship of copper, free radicals, and hepatitis. Conversely, in females, no apparent differences in clinical and biochemical changes were observed among the three groups. Causes for the discrepancy between the sexes remain to be clarified.

Alanine Transaminase↗
PubMed1992

Some chemical properties of the HCl-methanol extract from the puparial cuticle of Drosophila melanogaster.

1. The HCl-methanol (HCl-MeOH) soluble fraction from the puparial cuticle of yellow, black and ebony of D. melanogaster was hydrolyzed in hydrochloric acid and examined for beta-alanine, ketocatechol, and acetic acid. 2. Between beta-alanine and ketocatechol and between beta-alanine and acetic acid, a quantitatively inverse relationship was found, respectively. The former relationship was further confirmed by the feeding experiment of beta-alanine to black. 3. Of total beta-alanine in the HCl-MeOH extract, the proportion of those having free amino group was 74.8 per cent. 4. All these results indicate that the HCl-MeOH soluble fraction of the puparial cuticle may be useful for investigating the cross-link structure of the cuticle.

Acetates↗
PubMed1992

Charting of daily weight pattern reinforces maintenance of weight reduction in moderately obese patients.

To maintain reduced body weight by behavioral therapy in moderately obese patients, body weight was measured four times daily and charted in a weekly graph. Seventy-two female patients with simple obesity were divided into two groups: 55 patients with appliance of charting of weight pattern (group-I), and 17 patients without the charting (group-II). The percentage of patients followed for 2 years was different between group-I (87%) and group-II (65%) during 2 years after completion of weight reduction therapy interviews (p less than 0.05). Forty-eight of group-I patients succeeded in decreasing their weight by 15.2 +/- 1.5 (mean +/- SEM) kg during the 6.5 +/- 0.8 months of the therapy interviews. They were followed up for 3.8 years with no rebound weight gain. Eleven patients in group-II also succeeded in decreasing their weight by 16.8 +/- 1.9 kg during 7.8 +/- 1.3 months but their body weight rebounded by 9.0 kg during the 2-year followup period. Twelve of 15 male patients with weight charting maintained reduced weight during 4.3 years. It was easier and more effective for obese patients to maintain weight graphs for the longer period than to record no weight graphs. Obese patients could themselves monitor irregular weight patterns produced by overeating and correct the irregularities in food intake and daily lifestyles. This seems to explain why the illustration of daily fluctuations of weight measurements was useful for long-term maintenance of weight reduction.

Adult↗
PubMed1992

Pathogenesis of experimental otitis media with effusion caused by a combination of eustachian tube dysfunction and immunosuppression.

Inflammatory factors appear to play an important role in the development of otitis media with effusion (OME). However, otitis media experimentally induced by endotoxin injection or secondary immunoresponse was not persistent. In order to produce refractory OME, two pathologic conditions were necessarily combined: tubal ventilatory dysfunction and suppression of the immunologic defense mechanism by immunosuppressive drugs. In the presence of these two pathologic conditions, all cases that evidenced negative middle ear pressure due to tubal dysfunction developed OME. In the control group with either tubal dysfunction or immunosuppression alone, only 1 of 20 ears developed OME. Transtubal infection due to negative middle ear pressure caused by tubal ventilatory dysfunction may be one of the most important etiologic factors in OME.

Animals↗
PubMed1992

[Investigation of panipenem/betamipron levels in sera and various tissues in patients of orthopedic surgery].

Panipenem/betamipron (PAPM/BP), a new parenteral carbapenem antibiotic, was investigated with regard to their levels in sera and various tissues collected from patients under orthopedic surgery. The subjects were 17 patients, complaining low back pain and hospitalized for surgical operations. PAPM/BP was administered by intravenous drip infusion for 30 minutes of a dose of 500 mg/500 mg. Serum and cerebrospinal fluid (CSF) specimens were taken from 8 patients at 15-70 minutes after administration and assayed for PAPM and BP levels. Serum, bone, and joint capsule samples where taken from the other 9 cases at 25-127 minutes after administration and assayed. PAPM levels in CSF were considerably lower than those in serum. They were 23.74-1.11 micrograms/ml in sera, 0.31-0.05 micrograms/ml in CSF's during 15 to 70 minutes after administration. PAPM levels were 27.85-2.97 micrograms/ml in sera, 2.54-0.20 micrograms/g in bones, 5.63 and 1.67 micrograms/g in joint capsules during 25 to 127 minutes after administration. BP levels in sera and various tissues were low compared to those of PAPM. These results showed that PAPM was detected at higher levels than 0.2 microgram/g in various tissues, except CSF during 20 to 120 minutes after drip infusion of PAPM/BP 500 mg/500 mg for 30 minutes.

Adolescent↗
PubMed1991

Effects of D1 and D2 antagonists on the transient increase of dopamine release by dopamine agonists by means of brain dialysis.

The effects of selective D1 and D2 antagonists, R-(+)-8-chloro-2,3,4,5-tetrahydro-3-methyl-5-phenyl-1H-3-benzazepine-7- ol(SCH-23390) and sulpiride, on the transient increase of dopamine (DA) release induced by DA agonists, apomorphine (APO) and 2,3,4,5-tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine (SKF-38393) were examined in the caudate-putamen of freely moving rat by means of microdialysis during local coinfusion of a DA antagonist and agonist. Infusion of 10(-5) M and/or 10(-6) M concentrations of SCH-23390 suppressed a brief increase in DA release induced by both 10(-4) M of APO and 10(-5) M of SKF-38393. On the other hand, 10(-5) M and/or 10(-6) M of sulpiride exerted little or no effect. A possible explanation for this phenomenon was discussed.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed1991

Corticocortical inputs to the dorsal and ventral aspects of the premotor cortex of macaque monkeys.

Recent cytoarchitectonic, histochemical and physiological studies have shown that the lateral part of area 6 (the premotor cortex) of macaque monkeys can be divided into at least two subregions, each of which is considered to play an important role in motor control. One lies in the dorsal aspect of the premotor cortex (PMd) medial to the spur of the arcuate sulcus, and the other in the ventral aspect of the premotor cortex (PMv) lateral to it. Since there is little information on the corticocortical inputs to the PMd, wheat-germ agglutinin conjugated to horseradish peroxidase (WGA-HRP) was injected into both the PMd and PMv to study corticocortical inputs to these two regions, and the distribution of retrogradely labeled cells was compared. When WGA-HRP was injected into the region immediately lateral to the superior precentral sulcus within the PMd, retrogradely labeled neurons were found in area 6 lying in the mesial wall possibly corresponding to the supplementary motor area (SMA), areas 24 and 23 of the cingulate cortex, rostral region of area 4, and area 5 (area PEa). In contrast, when WGA-HRP was injected into the PMv immediately caudal to the arcuate sulcus and lateral to the spur of the arcuate sulcus, the labeled cells were found in area 7 (areas POa, PF, PFG), area 5 (area PEa), area PFop (secondary somatosensory area), SMA, the cingulate cortex (areas 24), caudal region of area 4 in the rostral bank of the central sulcus, and area 3a. It appears that the differences in the corticocortical inputs contribute to specialization of the PMd and PMv for their differential roles in motor control.

Animals↗
PubMed1991

A long-term outcome study of tardive dyskinesia in patients on antipsychotic medication.

We followed 28 patients with tardive dyskinesia (TD) (eight men and 20 women, mean age 55.1 years) for 11-12 years to elucidate the long-term outcome of TD. All the patients received their physicians' choice of therapy, mainly comprising antipsychotics. The severity of TD was assessed at 5 and 11-12 years after the baseline evaluation. TD did not disappear in any patient. The severity of TD was unchanged in 39.3%, and improved in 17.9% despite continuous treatment with low doses of antipsychotics (mean 221.4 mg chlorpromazine equivalent daily). TD fluctuated in 21.4% and worsened in only 21.4%. Outcome was not correlated with patient sex or age, duration of primary illness, dosage of antipsychotics, or changes in dosage. The initial severity of TD showed some relationship to outcome. The number of bodily areas affected by TD increased in some patients with unchanged TD severity.

Adult↗
PubMed1991

Effects of clomipramine on the concentrations of catecholamines, indoleamines and their metabolites in 11 rat brain regions.

The effects of clomipramine (CMP) treatment on the brain concentrations of catecholamines, indoleamines and their metabolites were evaluated in 11 rat brain regions. An acute CMP treatment (15 mg/kg) reduced only the 5-hydroxyindole-3-acetic acid (5HIAA) concentrations in all regions. A long-term CMP treatment (14 days, 10 mg/kg/day) decreased the concentrations of dopamine (DA), 5-hydroxytryptamine and 5HIAA in the mesencephalon, and increased the DA concentrations in the hippocampus. In comparison with the values for the long-term treated rats, an acute injection of CMP (15 mg/kg) after a long-term treatment increased the norepinephrine concentrations in the hypothalamus and amygdala, and the concentrations of DA, 3,4-dihydroxyphenylacetic acid and homovanillic acid in the basal ganglia. On the other hand, it failed to decrease the 5HIAA concentrations in the basal ganglia, frontal cortex, hypothalamus, cerebellum, pons + medulla oblongata, and mesencephalon.

Animals↗