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Biomedical subjects

H Kumashiro

Publications and source records attributed to H Kumashiro.

At least 55 records · Page 3Linked to original sources
PubMed1990

[Neuroexcitotoxic action of db-cAMP: lesioning of neuronal cell bodies while sparing fibers of passage].

In our previous study, we have demonstrated that intra-amygdaloid injection of dibutyryl-cAMP causes neuronal damage in the injected AM and the CA 1-3 subfields of the ipsilateral hippocampus in addition to epileptic seizures. This result suggested that db-cAMP is a new neuroexcitotoxin. In this study, we examined comparative morphological effect on acetylcholinesterase (AChE) following intra-amygdaloid injection of db-cAMP or, kainate. In Expt. 1, twenty rats received 100 micrograms db-cAMP (N = 10), 0.5 micrograms kainate (N = 4), or saline as a vehicle (N = 6), through the implanted cannula under non-anesthesia. Either kainate or db-cAMP produced epileptic seizures, while saline induced no electroclinical ictal response. Following db-cAMP or kainate injection, neuronal loss was observed in the injected AM, but AChE positive fibers were intact. In the hippocampus ipsilateral to the injected AM, the loss of pyramidal cells was also noted in accordance with the severity of seizure intensity. In the piriform cortex ipsilateral to the injected AM, the loss of AChE-positive fibers were seen, but sparing neuronal cell bodies. In Expt. 2, nineteen rats were injected with 100 micrograms db-cAMP (N = 7), 0.5 micrograms kainate (N = 7), or saline as a vehicle (N = 5) under pentobarbital anesthesia. Kainate or db-cAMP produced few sporadic spikes.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholinesterase↗
PubMed1989

Bidirectional transfer between kindling induced either by L-glutamate or L-aspartate and electrical stimulation in rats.

Repeated spaced injections into the amygdala (AM) of rats of a subconvulsive dose of either L-glutamate (GLU) or L-aspartate (ASP) produced progressive seizure development culminating in generalized convulsion strikingly similar to electrically kindled seizure. Both GLU- and ASP-kindled AM sites responded to electrical stimulation with very rapid development of kindled seizure. When electrically kindled AM sites received identical injections of GLU or ASP, a similar positive transfer effect was obtained. These results suggest that (1) either GLU or ASP alone can kindle the AM and (2) GLU, ASP or GLU/ASP kindling share common neurobiological mechanisms with electrical kindling.

Amygdala↗
PubMed1989

Chemical kindling induced by cAMP and transfer to electrical kindling.

Repeated injection of an initially subconvulsive dose of cAMP into the rat amygdala (AM) produced progressive seizure development similar to that of electrical kindling. The chemical kindling occurred in a dose-dependent manner. Furthermore, when cAMP was combined with EDTA, a strong inhibitor of cAMP phosphodiesterase, the seizure development was remarkably facilitated. When the animals that had been chemically kindled were subjected to electrical kindling, they rapidly developed seizures. These results, together with those previously published, suggest that cAMP participates in the seizure development induced by AM kindling.

Amygdala↗
PubMed1989

A case of temporal lobe astrocytoma associated with epileptic seizures and schizophrenia-like psychosis.

The clinical pictures of a left temporal lobe astrocytoma involving the hippocampal region showed a period of 27 years from ages 12 to 38 by epileptic seizures and a period of 9 years from 14 to 22 by schizophrenia-like symptoms and the following aggressive behavior during 16 years from ages 23 to 38. After a resection of the temporal lobe tumor sparing the hippocampus, transient delusions and aggressive behavior were observed. It might be considered that the hippocampus has the most suspectable relationship with the schizophrenia-like symptoms.

Adult↗
PubMed1989

[Substantia innominata kindling in rats].

With a combination of electrolytic lesion and choline acetyltransferase histochemistry, Kimura et al. suggested that cholinergic neurons in the substantia innominata (SI) plays an important role in accessing non-motor structure, such as the amygdala (AM), to the motor system during AM kindling. More recent studies demonstrated that intra-SI injection of GABAergic agent or excitatory amino acid antagonist suppresses the kindled generalized convulsion without blocking afterdischarge (AD) generation in the AM. In order to gain further insight into the role played by the SI in AM kindling, we examined the comparative electroclinical features of AM and SI kindling in addition to the transferability of the SI to the ipsilateral AM. Male Wistar rats were electrically kindled at the left AM or the left SI at the AD threshold (ADT) until five consecutive Stage 5 generalized convulsions were evoked. Subsequently, the stimulus intensity was gradually reduced and the last intensity to induce Stage 5 seizure was designated as the generalized seizure triggering threshold (GST). Following the determination of the GST, the SI stimulation was switched to the ipsilateral AM. All the animals were perfused and electrode placements were identified histologically. The electrode placements distributed in the medial SI (N = 5), lateral SI (N = 9), Globus Pallidum (GP) (N = 5) and Nucleus Accumbens (NA) (N = 2). All electrodes of the AM (N = 9) were located within the AM. The 3/5 of GP rats kindled, while the 2/5 did not kindle. The 2/2 of NA rats kindled.(ABSTRACT TRUNCATED AT 250 WORDS)

Amygdala↗
PubMed1989

[Suppressive effect of GABA-containing liposomes on kindled convulsion].

gamma-aminobutyric acid (GABA), a major neurotransmitter in the mammalian brain, may be natural mediator of defence against epileptic activities. When given peripherally, however, GABA itself can cross the blood-brain barrier (BBB) insufficiently. Liposomes (LIPO), being composed of lipid bilayers in which various compounds can be entrapped, have been shown to cross the BBB. Recently, Loeb et al. demonstrated that intraperitoneal injection of GABA entrapped within LIPO (GABA-L) significantly suppresses penicillin- or isoniazid-induced seizures in rats. In the present study, we examined the effect of intraperitoneally administered GABA-L on the kindled amygdala (AM) seizures in addition to the comparative uptake of radioactivity by brain following intraperitoneal administration of 3H-GABA-L or 3H-GABA in rats. Expt. I: Anticonvulsant effect of GABA-L Twelve male Wistar rats weighing 250-300 g were used. Bipolar electrodes made of twisted stainless steel wire 0.2 mm in diameter were implanted into the left AM. All the animals were kindled at the left AM until a stable kindled seizure was evoked for at least five successive days. Subsequently, the stimulus intensity was gradually reduced and the last intensity to induce the kindled seizure was designated as the generalized seizure triggerring threshold (GST). GABA was dissolved in deionized water at a concentration of 0.5 g/ml. GABA-L and LIPO were prepared as follows. 80 mumoles L-alpha-phosphatidylcholine, 22.8 mumoles stearylamine and 11.4 mumoles cholesterol were dissolved in chloroform. After chloroform was removed under a stream of nitrogen gas, dried thin film of phospholipids was formed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Bifunctional roles of catecholamines in the development of amygdala kindling demonstrated by continuous intra-amygdala infusion of 6-hydroxydopamine.

Details of seizure stage progression in amygdala kindling were studied in the cat under local denervation of catecholamine input to the amygdala. A chemitrode was used for both electrical stimulation and continuous infusion of 6-hydroxydopamine. The extent of denervation was confirmed by fluorescence histochemistry. The result has indicated that catecholamine afferents to the amygdala exert biphasic roles in normal kindling: inhibitory in the early local and late generalized seizure stages, whereas facilitatory in the intermediate stage.

Amygdala↗
PubMed1988

[Epileptic seizure model utilizing additive effects of excitatory amino acids].

L-glutamate (GLU) and L-aspartate (ASP), major excitatory amino acids in the brain, are believed to have an important role in the generalization and expression of epileptic seizures. Their analogues such as kainate, folate, ibotenate and quisqualate have been widely used to produce epileptic seizures, since they have a potent excitatory action. However, these analogues produce striking neuronal damage at the injection site when injected intracerebrally. Therefore, these analogues are not appropriate for studying the mechanisms of epilepsy, which is believed to be based on the functional changes of the brain. On the other hand, although GLU and ASP themselves have minimal neurotoxic action, a relatively higher dosage than that of their analogues is needed to produce epileptic seizures. A recent report, in which Freeman has found that combined GLU/ASP released from the lobster neuromuscular synapse in a molar ratio of 1:3 (GLU/ASP) produces strong excitation, may provide some clue to this problem. In this study, we examined the features of epileptic seizures and neuronal damage following the injection of GLU/ASP combined in this molar ratio into the amygdala (AM) of rats. Twenty-nine adult male Wistar rats weighing 200-250 g were used. All animals had received a cannula made of a 22-G stainless steel tube into the left AM. A bipolar recording electrode made of stainless steel wire was attached to its wall.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗
PubMed1988

[Facilitatory effect of calcium hopantenate on amygdaloid kindling in rats].

Calcium hopantenate (HOPA-Ca), which is obtained by substituting the beta-alanine of pantothenic acid for gamma-amino butyric acid (GABA), is a therapeutic drug for mental retardation and cerebrovascular dementia. HOPA-Ca is known to produce convulsive seizures in some patients although it is also true that this improves EEG abnormalities and suppresses epileptic seizures. Thus, clinical observations suggest that HOPA-Ca exerts a paradoxical influence on epilepsy. In order to gain further insight into the influence of HOPA-Ca on epilepsy, we examined its effects on the generalized seizure-triggering threshold (GST) of kindled amygdaloid (AM) seizure and on the rate of AM kindling in rats. Male Wistar rats weighing 200-250 g were used. Under pentobarbital anesthesia, a bipolar electrode, made of twisted stainless steel wire 0.2 mm in diameter, was stereotaxically implanted into the left AM. Daily electrical stimulation was given at the intensity of afterdischarge threshold (ADT). Electrical stimulation was continued until at least five consecutive generalized convulsions were evoked. Subsequently, the stimulus intensity was daily lowered by 20-microA steps and the last stimulus intensity for evoking generalized convulsion was designated as the GST. Experiment 1. Influence of HOPA-Ca on the GST; HOPA-Ca was dissolved in saline as a vehicle. Injections of 50, 100, 250, 500 mg/kg HOPA-Ca were given intraperitoneally 60 min before the stimulation at the GST. The GST never changed with vehicle injection. The GST increase was never observed with any amount of HOPA-Ca. However, the GST dropped flowing HOPA-Ca infection independent of its amount. The GST reduction was always 20-microA.(ABSTRACT TRUNCATED AT 250 WORDS)

Amygdala↗
PubMed1987

The application of DSM-III diagnostic criteria to school refusal.

The DSM-III diagnostic criteria were applied to school refusal cases, and the possibility of a subclassification of school refusal through the DSM-III was studied. The subjects were 50 cases diagnosed as school refusal following the criteria defined by Sumi and Tatara. As for the Axis I diagnoses, the subjects fell under the separation anxiety disorder (7 cases), avoidance disorder (13 cases), overanxious disorder (8 cases), identity disorder (5 cases), adjustment disorder (11 cases) and others. On Axis II, no case was diagnosed as having the personality disorder, but 14 cases showed pathological personality traits. On Axis III, nine cases showed some physical disorders or conditions. Among the five major diagnostic groups, there were some definite differences concerning the onset age, clinical course, psychosocial stress, response to therapy and prognosis of disorders. These results suggest the availability of a subclassification of school refusal by means of the DSM-III criteria.

Adolescent↗
PubMed1987

The diurnal variation and response to dexamethasone suppression test of saliva cortisol level in autistic children.

In order to examine the function of hypothalamic-pituitary-adrenal axis (HPA-axis) in autistic children, the diurnal rhythm of saliva cortisol and the response of cortisol to the DST was investigated using saliva samples. 1) The plasma and saliva cortisol levels showed a positive correlation in normal healthy adults. Moreover, the saliva cortisol level exhibited a similar diurnal rhythm and DST response as did the plasma cortisol level. 2) The saliva cortisol level in normal children showed a similar diurnal rhythm and DST response as that in normal healthy adults. 3) Some children with infantile autism showed an abnormal diurnal rhythm or DST response for saliva cortisol. Moreover, the latter abnormality was observed more frequently in poorly-developed cases than in highly-developed cases. 4) These results suggest that the negative feedback mechanism of the HPA-axis may be disturbed in autistic children, especially the poorly-developed cases, owing to a disorder in the regulation by serotonin metabolism.

Adolescent↗
PubMed1987

Clinical features of autistic children with setback course in their infancy.

This study examines the incidence rate of setback in 80 autistic children, the correlation between the type of onset and clinical features, developmental level and prognosis based on an originally developed questionnaire. Moreover, this study seeks to investigate the possibility that infantile autism might be classified into subgroups by the type of onset. 1) The acquired (including questionably acquired) group consisted of 39 cases (49%), while the natal group was made up of 41 cases (51%). 2) The age when the setback occurred was 21-22 months in the acquired group. 3) Precipitating psychological events were observed in 22 cases (56%) of the acquired group. 4) The mental developmental level including speech and socialbility function at 5 years of age was significantly lower in the acquired group than in the natal group. 5) The acquired group showed severe behavioral disorders such as "stereotypic behavior," "extremely hyperkinetic behavior" and "self-abusive behavior" compared with the natal group. 6) The adaptive levels at schools or institutions were lower in the acquired group than in the natal group. 7) There was a higher incidence of epileptic seizures or febrile convulsions in the acquired group than in the natal group. Moreover, there was a higher incidence of severe perinatal abnormalities in the acquired group. 8) The above-mentioned results suggest that infantile autism might be classified into two subgroups, acquired and natal groups, based on the type of onset, and also suggest that some types of brain dysfunctions are more severe in the acquired group than in the natal group.

Age Factors↗
PubMed1987

[The groping phenomena in a case of Alzheimer type dementia].

We reported a case of senile dementia, Alzheimer type, with groping in response to a visual stimulus ("visual groping"). T.S. was a right-handed woman, 69 years old. In the beginning she displayed "visual groping" of the right hand, besides aphasia, lowered registration and Casteigne's "Motor neglect" of the right upper extremity. As the disease progressed, "visual groping" of the left hand developed, followed by "forced grasping" of the left hand. When the patient was 62 years old, she first showed decreased volition and lowered registration. Later poor finger movement and lessened speech were marked. At the age of 69, she was admitted to our hospital with aphasia and reduced registration. The patient showed preservation in naming and drawing tests. She also displayed a "visual groping" phenomenon of the right hand. This phenomenon was revealed when an examiner displayed something about 50 cm in front of the patient, and then she extended the upper extremity gropingly. We considered this phenomenon as "groping in response to a visual stimulus" of Denny-Brown. At the same time, the motor or praxic disorder of this patient consisted of paucity of movement. When she was told to imitate, her right upper extremity was hardly utilized, although later movements could be realized by her practice. When she was told to pour water from one glass into another, she used her left hand, although she used her right hand for spontaneous actions. So we considered this dyspraxia as a motor neglect of Casteigne.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗