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Biomedical subjects

Y Nakada

Publications and source records attributed to Y Nakada.

At least 19 recordsLinked to original sources

A study of psychosocial factors in the psychosomatic symptoms of adolescents in Okinawa.

High school students (N = 902) in Okinawa were asked to participate in a questionnaire survey which was designed to investigate the psychosocial factors in the psychosomatic symptoms of adolescents. The questionnaire focused on mental distress, perception of school and home environment and psychosomatic symptoms. The Japanese Edition Cornell Medical Index-Health Questionnaire (JCMI) for evaluating emotional instability and the New TK Diagnostic Test for Parent-Child Relationship were also utilized. Distress in relationships with family or friends, finding little pleasure in school and/or home, showing emotional instability as diagnosed according to regions III and IV of JCMI, or showing strained parent-child relationships according to the TK Test items were found to be closely associated with psychosomatic symptoms. In addition, students with human relations problems, especially family problems, tended to have a strained relationship with parents and tended to show autonomic hyperactivity represented by orthostatic dysregulation. Students with peer problems tended to have emotional instability and to find little pleasure in school; they had mental as well as urinary and bowel symptoms. The findings of this study suggest that distresses in family or peer relationships, emotional instability and a strained parent-child relationship are important factors in the onset of psychosomatic symptoms in adolescents.

Adolescent

[Determination of the main metabolite (desethyl KBT-3022) of a new antiplatelet agent, KBT-3022 in plasma by gas chromatography].

A highly sensitive, accurate and reproducible gas chromatographic method for the determination of a main metabolite, 2-[4,5-bis(4-methoxy-phenyl)thiazol-2-yl] pyrrol-ylacetic acid (desethyl KBT-3022) of a new antiplatelet agent, ethyl 2-[4,5-bis(4-methoxyphenyl)thiazol-2-yl]pyrrol-1-ylacetate (KBT-3022), in the human or dog plasma has been developed. Desethyl KBT-3022 in the plasma was extracted with a mixture of n-hexane and dichloromethane (1:1), and was derivatized using pentafluorobenzyl bromide. The obtained pentafluorobenzyl derivative of desethyl KBT-3022 in the plasma was separated by high-performance liquid chromatography. After the separation, the pentafluorobenzyl derivative of desethyl KBT-3022 was detected by gas chromatography. Gas chromatography was performed with a Ultra 1 column (12 m x 0.22 mm i.d., film thickness 0.33 microns), using an electron capture detector. 2-[2-(4,5-Bis(4-methoxyphenyl)thiazol-2-yl)pyrrol-l-yl]propionic acid was used as an internal standard. The detection limit of desethyl KBT-3022 in the plasma was 0.2 ng/ml. The coefficients of variation were below 5.3%. This method was applied to the determination of the plasma concentration of desethyl KBT-3022 after oral administration of KBT-3022 to dogs.

Administration, Oral

A case of eosinophilic granuloma arising in the mandible.

Eosinophilic granuloma is a disease of the reticuloendothelial system and its pathogenesis is not yet completely clear. The histopathological findings are granulomatous proliferation of histiocytes accompanied by diffuse infiltration of eosinophils. We recently experienced a case of eosinophilic granuloma arising monostotically in the body of the mandible in the 76 [symbol: see text] region. There has been no local recurrence 17 months after surgical removal of the lesion.

Adolescent

Use of two miniplates for intermaxillary skeletal fixation in the treatment of jaw deformity and fracture.

Special techniques of skeletal intermaxillary fixation are described, which may be used in edentulous patients or those with many missing teeth or multiple fractures of the jaw. Two such cases are described in which the usual fixation techniques could not provide sufficient stabilization because of linguoversion and mesioversion or lack of teeth, resulting in inability to maintain a vertical interocclusal relationship. Two long eight-hole Champy miniplates were therefore used distally to the canines on both sides. In the first case, they provided fixation following a sagittal ramus osteotomy to advance the mandible, and in the second case they were used in the treatment of a mandibular fracture.

Adult

[Anxiolytic effects of lisuride and its agonistic action to central 5-HT1A receptors].

Effects of lisuride, a derivative of ergot alkaloid, on central 5-HT1A receptors were investigated biochemically, behaviorally and electroencephalographically (EEG) in rats and rabbits. Effects of lisuride in water-lick conflict tests were also investigated in rats. Lisuride was found to strongly inhibit the bindings of [3H]8-OH-DPAT to 5-HT1A receptors in the raphe nucleus, hippocampus, cortex, amygdala and hypothalamus of rat brain. Inhibitory effects of lisuride on bindings of [3H]8-OH-DPAT in the hippocampus was almost the same as that of 5-HT (Ki = 0.5 nM) and stronger than those of the 5-HT agonist 5-MeO-DMT (Ki = 2.1 nM) or other ergot derivatives (bromocriptine and pergolide, Ki = 3.0 nM). Lisuride (0.1-0.5 mg/kg, i.p.), like 8-OH-DPAT, dose-dependently induced a 5-HT behavioral syndrome in rats. Lisuride affected locomotor activity in rats, whereas 8-OH-DPAT did not. In hippocampal EEG of rabbits, lisuride (0.01-0.03 mg/kg, i.v.), like 8-OH-DPAT and diazepam, dose-dependently inhibited rhythmical slow activity (RSA) induced by acoustical stimulation (3100 Hz) and also inhibited the RSA increased by administration of anxiogenic FG7142. In water-lick conflict tests, lisuride (0.05-0.1 mg/kg, i.p.), like diazepam, increased the number of shocks. These findings indicated that lisuride acts as a strong agonist on central 5-HT1A receptors and suggested that lisuride might be a potential anxiolytic.

Animals

[Interaction of the hypnotic lormetazepam with central benzodiazepine receptor subtypes omega 1, omega 2 and omega 3].

To clarify the action of lormetazepam, 3-hydroxybenzodiazepine, on the benzodiazepine (BZ) receptor subtypes, effects of lormetazepam on motor performance in the traction test and hexobarbital-induced loss of righting reflex in mice and the binding to BZ receptor subtypes were investigated in comparison with those of other BZ hypnotics. Lormetazepam prolonged the duration of hexobarbital-induced loss of righting reflex. The minimal effective dose (1 mg/kg, p.o.) was higher than that of flunitrazepam, lower than those of diazepam and zopiclone, and the same as those of triazolam and brotizolam. Lormetazepam showed the ataxic effect at 10 mg/kg, p.o., but the separation between its effective doses for the hypnotic and ataxic effects was the largest among the hypnotics tested. In the displacement study on [3H]flumazenil binding to cerebellar and spinal cord membranes, lormetazepam bound with a higher affinity to omega 1 receptor (Ki = 10 nM) than to omega 2 receptor (Ki = 29 nM). The GABA-ratios of lormetazepam to omega 1 and omega 2 receptors were 3.9 and 4.0, respectively; and they were higher and lower than those of flunitrazepam to omega 1 and omega 2 receptors, respectively. In the displacement study on [3H] Ro5-4864 binding to kidney membranes, lormetazepam bound with a lower affinity to the omega 3 receptor (Ki = 213 nM) than flunitrazepam. Thus, lormetazepam was suggested to be a potent hypnotic with weaker ataxic effects than other BZ hypnotics, which may be due to its selective and potent agonistic action on central omega 1 receptors.

Animals

Portable digital subtraction angiography in the operating room and intensive care unit.

A simple, inexpensive method of portable digital subtraction angiography (DSA) using an image processor (Sigma X), still-videorecorder and control panel combined with a surgical x-ray television unit can provide real time subtraction images on the monitor. This portable DSA unit was used in 161 cases (130 in the operating room and 31 in the intensive care unit). In the operating room it is useful: 1) to confirm patency of the parent artery and its branches after aneurysm clipping, 2) to identify feeding arteries of arteriovenous malformation and to confirm total extirpation, 3) to confirm the patency of extracranial-intracranial bypass, 4) to confirm patency of the internal carotid artery and absence of flap formation after carotid endarterectomy. In the intensive care unit, it is particularly useful for visualizing cerebral vasospasm after subarachnoid hemorrhage and recanalization of an occluded major intracranial artery. Absence of intracranial circulation can be demonstrated in patients with suspected brain death.

Angiography, Digital Subtraction

Hypersensitivity of rat glioma sublines with acquired ACNU resistance to L-asparaginase.

Cell lines resistant to 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3- (2-chloroethyl)-3-nitrosourea hydrochloride (ACNU) show a high degree of collateral sensitivity to L-asparaginase. The mechanism for this phenomenon was investigated by comparing the nutritional requirements and asparagine synthetase activity of the resistant sublines to those of parent cells. Nine ACNU-resistant sublines were isolated from rat glioma 9L cells after incubation with various concentrations of ACNU in Ham's F-12 medium. The 9L cells grew independently of asparagine, developing well in asparagine-deficient Dulbecco's modified Eagle's medium. In contrast, the growth rates of all nine ACNU-resistant sublines decreased under the same conditions and required the addition of 10(-4) M asparagine for maximum growth. Asparagine synthetase activity in the ACNU-resistant cells was much lower than in the 9L cells, suggesting that the requirement for asparagine in the resistant sublines was due to reduced activity of this enzyme. A growth-inhibition assay showed that the ACNU-resistant sublines were more sensitive to L-asparaginase than 9L cells by up to 2 x 10(5)-fold. These results suggest that L-asparaginase therapy has the potential to become a new approach for treating acquired ACNU resistance.

Animals

Synthesis of 5-keto-5-oxime derivatives of milbemycins and their activities against microfilariae.

Starting from milbemycin D (1), milbemycin A4 (2) and milbemycin A3 (3), a series of 5-keto-5-oxime derivatives were synthesized by selective oximation at the alpha,beta-conjugated carbonyl function of the 5-ketomilbemycins (4-6). The activities of the synthesized compounds were studied in dogs naturally infested with microfilariae of Dirofilaria immitis. The 5-keto-5-oximes of milbemycin D (7), A4 (8) and A3 (9) had quite high efficacy to control the microfilariae and more potency than their parents, while the 5-O-acyl oximes (11-15) also exhibited high activity.

Animals

[Surgical treatment of intracranial hematoma in an infant with hemophilia B (author's transl)].

Surgical experience of intracerebral hematoma in an 8-month-old boy with severe hemophilia B, which was not diagnosed preoperatively, was presented. Carotid angiography and removal of hematoma by craniotomy were carried out quite safely under fresh-blood-transfusion. After several months ventriculoperitoneal shunt was placed, because of progressing hydrocephalus and multiple porencephaly, this time, under the cover of the factor IX complex. The clinical features of the intracranial hemorrhage in hemophilia were discussed, with analysis of 52 operation cases. Whenever we encounter a patient with intracranial hemorrhage, especially in infancy, hemorrhagic diseases, as hemophilia, must always be borne in mind. Although intracranial hemorrhage is still the most fatal complication of hemophilia, the surgical risk has been greatly diminished by advanced replacement therapy. We stress the need of immediate diagnosis and positive surgical treatment with adequate replacement therapy, if indicated.

Blood Transfusion