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Biomedical subjects

J Oki

Publications and source records attributed to J Oki.

At least 37 records · Page 2Linked to original sources
PubMed1997

Serial imaging in MELAS.

We report two patients with fatal mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). Single-photon emission computed tomography (SPECT) with 123I-N-isopropyl-p-iodoamphetamine was more sensitive to the lesions than CT or MRI. SPECT showed focal hyperperfusion before or during the stroke and diffuse hypoperfusion of the brain, sparing the basal ganglia in the terminal stages. These findings support the theory that metabolic disturbance in the brain causes the "stroke" in MELAS.

Amphetamines↗
PubMed1997

Classical Rett syndrome in sisters: variability of clinical expression.

Familial cases of Rett syndrome (RS) are rare. No significant differences have been reported in the clinical courses of concordant monozygotic twins with RS. We present the variability of clinical expression in two Japanese sisters with classic RS. The younger sister, currently 6 years and 6 months old, never stood or walked alone, showed severe spasticity, growth retardation, and microcephaly and developed sleep-wake rhythm disturbance from age 4 years and seizures from age 5 years. The elder, currently 7 years and 9 months old, walked alone and had mild spasticity, no growth retardation, normal sleep-wakefulness rhythm and no seizures. RS is most likely to be transmitted as an X-linked dominant, male-lethal (XDML) disorder, although this is still contested. If RS is an XDML disorder, lyonization may account for variability of expression in the sisters.

Child↗
PubMed1997

L1CAM mutation in a Japanese family with X-linked hydrocephalus: a study for genetic counseling.

Mutations in the gene encoding neural cell adhesion molecule L1 (L1CAM) are involved in X-linked hydrocephalus (HSAS, hydrocephalus due to stenosis of the aqueduct of Sylvius), MASA syndrome (mental retardation, aphasia, shuffling gait, and adducted thumbs), and spastic paraplegia type 1. We examined the L1CAM mutation in a Japanese family with HSAS for the purpose of DNA-based genetic counseling. The proband was a 9-year-old boy who had a 1-bp deletion in exon 22 of the L1CAM gene. This resulted in a shift of the reading frame, and introduction of a premature stop codon. Translation of this mRNA will create a truncated protein without the transmembrane domain, which cannot be expressed on the cell surface. Magnetic resonance images (MRI) revealed markedly enlarged lateral ventricles, hypoplastic white matter, thin cortical mantle, agenesis of the corpus callosum and septum pellucidum, and a fused thalamus. These findings represented impaired L1CAM function during development of the nervous system with resultant adhesion between neurons, neurites outgrowth and fasciculation, and neural cell migration. Screening by Apa I digestion of polymerase chain reaction (PCR) products identified the mother and the younger sister as heterozygous carriers. The carriers were asymptomatic. The father and the other sister did not have the mutation. The identification of L1CAM mutation in families with HSAS will give them the opportunity for DNA-based counseling and prenatal diagnosis.

Child↗
PubMed1997

Pyruvate dehydrogenase complex deficiency with multiple minor anomalies.

Pyruvate dehydrogenase complex (PDHC) deficiency is known to cause congenital lactic acidosis. The case of a 9-month-old female infant with PDHC deficiency caused by a mutation in exon 11 of the pyruvate dehydrogenase (PDH) E1 alpha gene is described. Her facial features were as follows: frontal bossing, upslanting palpebral fissures, a short upturned nose, a long philtrum and low set ears. These anomalies are characteristic not only of a malformation syndrome or chromosomal aberration, but also of PDHC deficiency. Because PDHC deficiency requires early treatment, metabolic disorders should be kept in mind in a patient with dysmorphic features. Further, she had multiple minor anomalies including bilateral inguinal herniae, an umbilical hernia and small hands and feet, which have not been described in previous reports.

Abnormalities, Multiple↗
PubMed1997

Developmental regulation of spinal motoneurons by monoaminergic nerve fibers.

1. In rats, both diameter and area of the cell bodies of spinal MNs increase rapidly during the first few postnatal weeks and slowly thereafter. The total dendritic length, radial extent and arbor area of spinal MNs also increase significantly throughout the first few postnatal weeks. This development is coincident with motor development in rat, which progresses rapidly during the first two to four weeks of life. The dendritic length and radial extent of spinal MNs increase more significantly in the cervical cord than in the lumbar cord throughout the first three postnatal days, and are possibly related to the motor development, with a rostro-caudal gradient. 2. All monoaminergic neurons projecting their axons to the spinal cord are located in the brainstem. namely in the locus coeruleus, the subcoeruleus and the medulla raphe nuclei in rats. The NA neurons of the locus coeruleus begin to be detected at ED 10-13, slightly earlier than the 5HT neurons in the raphe nuclei, which are first detected at ED 13. At ED 16, the NA fibers are seen in the ventral funiculus only at the cervical level, and many NA fibers are seen in the ventral horns at all levels at ED 18. The 5HT fibers reach the caudalmost levels of spinal cord by ED 16-17, which is earlier than NA fibers; this occurs in spite of the earlier ontogeny of NA neurons in the locus coeruleus than that of 5HT neurons in the raphe nuclei. 3. The monoamine system is thought to exert a variety of modulatory effects on target neurons during both pre- and postnatal periods, and many reports support the idea that monoamine systems have a "neurotrophic effect." On the other hand, important roles of NA and 5HT in MN activity and/or motor behavior have also been reported. It is suggested, therefore, that monoaminergic systems play important roles in motor development through a two-step mechanism: during early developmental stage. monoaminergic systems mainly act as neurotrophic agents on spinal MNs, which are the final motor output neurons; thereafter, they mainly play neuromodulatory roles on MN activities.

Animals↗
PubMed1997

[Effects of melatonin and diazepam on the eye movement and postural muscle tone in decerebrate cats].

We studied the effects of melatonin and diazepam on eye movement and muscle activity in decerebrate cats, and results were compared with those obtained from carbachol injection into the pontine reticular formation which was supposed to be a model of REM sleep. In precollicular postmammillary decerebrate cats, the horizontal eye movement and the activity of bilateral triceps surae muscles were recorded under three conditions: (1) microinjection of carbachol into the rostral pontine reticular formation; (2) intravenous administration melatonin; and (3) diazepam. Both rapid eye movement and reduction of muscle activity were induced by carbachol injection, while only reduction of muscle activity was induced by diazepam administration. Neither rapid eye movement nor reduction of muscle activity was induced by melatonin administration in this animal preparation. From these results, we speculated that the inhibitory effect of diazepam on muscle tonus was not manifested through activation of the brainstem REM generating system. It is known that the melatonin receptors are located in several sites of central nervous system, such as suprachiasmatic nucleus, and not in the brainstem and spinal cord. The present results of melatonin administration may support this fact in view of behavioral aspects.

Animals↗
PubMed1996

Developmental changes in the noradrenergic innervations of spinal motoneurons in neonatal rats.

Developmental changes in the noradrenergic innervations of spinal motoneurons in both the cervical and lumbar cords were studied in neonatal rats. The labeling of motoneurons was done using choleratoxin B subunit as a retrograde neurotracer. The noradrenergic fibers were detected by immunohistochemistry for tyrosine hydroxylase. At postnatal day 1, tyrosine hydroxylase immunoreactive fibers were evident in the entire ventral horn, including the triceps brachii motoneuron pools at the cervical level. In contrast, they were observed only in that portion of the ventral horn medial to the quadriceps femoris motoneuron pools at the lumbar level. Subsequently, tyrosine hydroxylase immunoreactive fibers increased at both levels, and they were distributed in most of the gray matter at postnatal day 14. At this age, the distribution pattern of tyrosine hydroxylase immunoreactive fibers in the lumbar level was almost identical to that of the cervical level. The number of closely apposed tyrosine hydroxylase immunoreactive varicosities on motoneurons (close appositions) increased continuously from postnatal day 1 to 14 at both the cervical and lumbar levels. At postnatal day 1, triceps brachii motoneurons had more close appositions than quadriceps femoris motoneurons in number and, after postnatal day 7, there was no difference in the number of close appositions between triceps brachii motoneurons and quadriceps femoris motoneurons. Based on these results, we discuss the significance of monoaminergic influences on the postnatal development of spinal motoneurons and of motor behavior with a rostrocaudal gradient.

Adrenergic Fibers↗
PubMed1996

Intraoperative electrocorticography in children with medically intractable epilepsy.

Intraoperative electrocorticography (ECoG) was performed to localize epileptic foci in 20 children undergoing temporal and extratemporal surgery for intractable epilepsy under modified neuroleptanalgesia. Nitrous oxide gas was discontinued at least 15 minutes before and during preresection ECoG recording, which lasted for 30 minutes. Seventeen patients showed epileptiform discharges on preresection ECoG. Hyperventilation loading, monitored by electroencephalography or ECoG in all patients, induced enhanced or induced epileptiform activities in 17 patients and provoked electroencephalographic seizures in 10 patients. All foci in non-eloquent areas were resected. Fifteen patients have been seizure-free with reduced medication, and two patients have achieved worthwhile improvement. Habitual seizures have remained in three patients. Two of these patients had foci in eloquent areas which could not be resected. Intraoperative ECoG can improve the outcome of surgery for intractable epilepsy by localizing epileptic foci for resection.

Adolescent↗
PubMed1996

[A longitudinal study of three-year-old children with delayed development of language].

UNLABELLED: From January 1982 to December 1986, 113 three-year-old children (100 boys and 13 girls) visited the department of pediatrics, Asahikawa Medical College, because of delayed development of language (their expressive language age less than two-year-old). Of these children, 102 children (90%) have visited until they graduated from junior high school for the evaluation of intelligence quotient (IQ), diagnosis, the type of attended school and complications. The mean follow-up period was 10.8 years. The 113 children ware classified as 32 cases of developmental language disorder (DLD), 38 of autistic disorder (Au), 39 of mental retardation (MR), and 4 of deafness based on the results of clinical examination (DSM-III-R), ABR and WPPSI/WISC-R. The purpose of this study is to compare the assessment of language development at the age 3 with the prognosis for intelligence, academic achievement and behavioral adjustment. At the age of three, we divided them into three groups using the Enjoji shiki hattatsu kensa-hyo. Group A including 31 children (29 boys and 2 girls) means delayed development in verbal expression only. Group B including 23 children (17 boys and 6 girls) means delayed development in verbal expression and comprehension. Group C including 59 children (54 boys and 5 girls) means delayed development not only in verbal expression and comprehension but also in communication skills. RESULTS: ABR: Four (2 boys and 2 girls) of 113 children did not show any significant waves on ABR at aged 3, and were also diagnosed as deafness by another audiometry. Comparison between the assessment of verbal expression at aged 3 and full scale IQ (FSIQ): FSIQs in 77% of group A were more than 70, while FSIQs in 79% of groups B and C were 70 or below. The assessment of verbal comprehension at aged 3 was significantly related with FSIQ (x2 = 23.88, p < 0.01). Classification of disorders and type of schools according to the assessment at aged 3: [Group A] Thirty one children were classified as 25 cases of DLD and 6 of MR. Before a graduation from junior high school, 20 children attended regular classes and 8 attended special classes for MR. [Group B] Twenty three children were classified as 4 cases of DLD, 10 of MR, 5 of Au and 4 of deafness. Before a graduation from junior high school, 4 children attended regular classes, 8 attended special classes for MR, 6 attended special schools for MR and 4 attended schools for deafness. [Group C] Fifty nine children were classified as 3 cases of DLD, 23 of MR and 33 of Au. Before graduating from junior high school, 10 children attended regular classes, 18 attended special classes for MR, 19 attended special schools for MR and 2 entered educational facilities. CONCLUSION: 1. Poor mental outcome could be predicted by delayed development of both expressive and comprehensive language, particularly associated with dysfunction of communication skills at the age of three. 2. ABR is a useful method for detecting of hearing loss in non-cooperative young children with delayed development of language.

Attention Deficit Disorder with Hyperactivity↗
PubMed1995

Acute transverse myelitis caused by ECHO virus type 18 infection.

UNLABELLED: A 14-year-old boy developed acute quadriplegia, associated with sensory impairment and bowel and urinary dysfunction. MRI of the cervical cord showed diffuse increased signal intensity on T2-weighted images with gadolinium-diethylenetriamine penta-acetic acid enhancement. Based on the clinical presentation and MRI findings, the diagnosis of acute transverse myelitis was made. Enterovirus RNA was amplified from CSF by the reverse transcriptase-polymerase chain reaction. Serum neutralizing antibody to ECHO virus type 18 rose from 1/4 on admission to 1/16 2 months later. CONCLUSION: This is the first reported case of acute transverse myelitis caused by ECHO virus type 18 infection.

Acute Disease↗
PubMed1995

Alobar holoprosencephaly with diabetes insipidus and neuronal migration disorder.

A 2-year-old girl with alobar holoprosencephaly associated with facial abnormalities, central diabetes insipidus, and a neuronal migration disorder is reported. The diagnosis of diabetes insipidus was based on low urine osmolality and low plasma ADH concentration during a water deprivation test, and clinical and biochemical improvement after desmopressin acetate administration. Because the posterior portion of the pituitary was located in the sella turcica and the hypothalamo-pituitary stalk was intact, the diabetes insipidus was presumed to have been caused by hypothalamic osmoreceptor dysfunction. MRI findings were compatible with alobar holoprosencephaly. In addition, heterotopic gray matter was recognized as a continuous band over a single ventricle. Defective cleavage of the prosencephalon associated with a neuronal migration disorder is characteristic of alobar holoprosencephaly.

Brain↗
PubMed1995

Ictal HMPAO-single photon emission computed tomography findings in reading epilepsy in a Japanese boy.

Reading epilepsy is rare. We report a 14-year-old right-handed Japanese boy who had had jaw jerking only while reading since age 12 years. The episodes occurred every time he read an English textbook and sometimes during prolonged reading of a Japanese textbook. The jaw jerking evolved to generalized tonic-clonic seizures (GTCS) on only two occasions during prolonged reading aloud. Routine EEGs showed no abnormality. After a few minutes of reading, however, the EEG showed bilateral 2-Hz, 150-microV spike-wave complexes with left frontotemporal accentuation, accompanied by jaw jerking. Ictal single photon emission computed tomography (SPECT) with [99Tc]hexamethylpropylene amine oxime (HMPAO) showed focal hyperperfusion of the frontal lobes bilaterally and of the left temporal area. Interictal SPECT and magnetic resonance imaging (MRI) were normal. The combination of valproate (VPA) and clonazepam (CZP) almost eliminated his symptoms. Ictal SPECT is a useful technique for seizure localization in reading epilepsy.

Adolescent↗