The role of different X-inactivation pattern on the variable clinical phenotype with Rett syndrome

A gene for Methyl-CpG binding protein 2 (MECP2), which locates Xq28, was recently found to be responsible for Rett syndrome. Although mutational analyses of MECP2 in Rett syndrome have been extensively analyzed, the mechanism(s) by which variable clinical phenotype occurred between affected monozygotic twins or sisters have not been clarified. We hypothesized that the difference of X-inactivation pattern might explain this phenomenon. With the method based on methylation-specific PCR, we analyzed polymorphic trinucleotide repeat in the human andorogen receptor gene mapped on Xq11.2-12, using DNA samples derived from previously described monozygotic twins and sisters together with their parents. Their clinical phenotypes were reported to be significantly different between siblings. We found that (1) maternally derived allele is predominantly active than paternally derived one in three out of four patients analyzed, (2) remaining one twin patient, whose ratio of active paternal allele is almost the same level as maternal allele, showed far much severe phenotype when compared with her counterpart. Together with the finding that most of the alleles with de novo mutation are from paternal X chromosome in sporadic cases, the existence of a mechanism that suppresses mutated paternal allele activation, resulting skewed X-inactivation to make clinical phenotype milder, might be speculated. Thus, when this mechanism fails to work sufficiently by an unknown reason, severer clinical phenotype could occur.

Engineering neoglycoproteins with multiple O-glycans using repetitive pentapeptide glycosylation units

Controlled protein remodeling with O-linked glycans has been limited by our incomplete understanding of the process of glycosylation. Here we describe a secretable fibroblast growth factor (FGF) with multiple mucin-type O-glycans produced by introducing a minimum pentapeptide glycosylation unit in a decarepeat format at its N- or C-terminus. Expressed in Chinese hamster ovary cells, chemical and biochemical analyses of the resultant proteins (Nm10-FGF and Cm10-FGF, respectively) demonstrated that all O-glycosylation units were glycosylated and the dominant structure was sialylated Gal[beta1-3]GalNAc. This indicates that minimum O-glycosylation unit in multirepeat format serves as a remarkably efficient acceptor in CHO cells. The Nm10-FGF and Cm10-FGF proteins maintained the mitogenic activity to vascular endothelial cells. In addition, intact Cm10-FGF and its desialylated form interacted with several lectins in the same way as mucin-type glycoproteins. The intact Cm10-FGF with multiple sialylated O-glycans exhibited a longer lifetime in circulating blood, whereas the Cm10-FGF with desialylated O-glycans exhibited a shorter lifetime than the deglycosylated form of Cm10-FGF. Our approach would thus appear to be highly effective for engineering neoglycoproteins, the characteristics of which are determined by their multiple mucin-type O-glycans.

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.

[Longitudinal study of cognitive function in two patients with focal cortical dysplasia]

To clarify the relationship between epileptic attacks and cognitive dysfunction, we examined the serial findings of 123I-IMP single photon emission computed tomography (SPECT) in relation to the intelligence quotient (IQ), assessed by Wechsler Intelligence Scale of Children-Revised, in two female patients with focal cortical dysplasia (FCD) over a 10-year period. The age of patient 1 at the initial assessment was 2 years, and the age of patient 2 was 9 months. They developed complex partial epilepsy in infancy, and were treated with antiepileptic drugs, which remained effective until 11 years of age, when their epileptic attacks recurred. Patient 1, a 14-year-old girl with FCD of the left parietal lobe suffered from dyscalculia, right-left disorientation, and finger agnosia even when she was free of epileptic attacks. Following the recurrence of seizures which occurred every night, she became unable to understand what was said to her. A hypoperfusion area detected by 123I-IMP SPECT was restricted to the left parietal lobe during the seizure-free period, but spread to the temporo-parietal lobes following the recurrence. Her verbal IQ declined from 94 (at 9 years of age) to 63 (at 11 years and 8 months). After her seizures were controlled again (at 14 years and 4 months), the 123I-IMP SPECT findings improved. Patient 2, a 12-year-old girl with FCD of the left frontal lobe, showed cognitive dysfunction. Her verbal IQ declined from 91 (at 7 years and 5 months) to 76 (at 11 years and 8 months) following a recurrence of epileptic attacks. 123I-IMP SPECT showed hypoperfusion in the left frontal lobe, where the accumulation count ratio (left/right ratio) declined from 0.86 (at 3 years) to 0.64 (at 11 years). These findings suggest that epileptic attacks are related to cognitive dysfunction in FCD patients. This cognitive dysfunction appears to correlate with the appearance of hypoperfusion areas, as detected by 123I-IMP SPECT.

Cerebellar hypoperfusion and developmental dysphasia in a male

A male with developmental dysphasia is documented with fine motor dysfunction whose improvement in expressive language was associated with increased cerebellar perfusion, as detected by serial N-isopropyl-p-[iodine-123] iodoamphetamine single photon emission computed tomography (SPECT). His expressive language has been improving since 6 years, 8 months of age, and his verbal intelligence quotient improved from less than 45 at 5 years of age to 80 at 8 years of age. Compared with the SPECT findings at 4 years of age, the ratio of the average pixel values of the cerebellum to the frontal cortices increased at 9 years of age (from 0.81 to 1.03-1.09 in the hemisphere and from 0.66 to 0.98 in the vermis). However, he was not able to understand stories presented orally even at 9 years, 4 months of age. These results suggest that developmental dysphasia, which mostly involves expressive impairment, in this patient could have been the result of delayed maturation of cerebellar function, mainly that of the vermis.

Development of spinal motoneurons in rats after a neonatal hypoxic insult

To determine the developmental changes of cervical and lumbar motoneurons (MNs) during normal development and after a neonatal hypoxic insult, cervical and lumbar MNs were studied in rats of various postnatal ages using a retrograde neurotracing technique combined with immunohistochemistry. The results regarding normal development could be summarized as follows: (1) the dendrites elongated mainly during the first 5 postnatal days (PNDs), being longer and more extensive in cervical MNs than in lumbar MNs; (2) the average cell body area increased from PND 5 to 14; and (3) the distribution of cell body areas changed from a unimodal to a bimodal pattern between PND 5 and 14. The temporal differences in morphologic development between cervical and lumbar MNs may influence the motor development in a rostrocaudal manner. The dendrites of lumbar MNs were shorter and less extensive in rats with a neonatal hypoxic insult than in rats without one; no significant difference was observed in cervical MNs between the two groups. The developmental difference between cervical and lumbar MNs after a neonatal hypoxic insult may contribute to motor deficits, with greater effect on the lower than the upper limbs.

[A successful treatment with intravenous lidocaine followed by oral mexiletine in a patient with Lennox-Gastaut syndrome]

Clusters of atypical absence, myoclonic seizures and tonic seizures developed in a thirteen-year-old boy with Lennox-Gastaut syndrome. As conventional antiepileptic drugs failed to eliminate the seizures, we treated the patient with continuous intravenous lidocaine (4 mg/kg/hr). The treatment reduced the duration of paroxysmal discharges (spike-wave complexes and rapid rhythm) from 3 sec/min to 0.7 sec/min, monitored by EEG. Oral mexiletine (5.4 mg/kg/day) following the lidocaine treatment has maintained good seizure control for two years with no adverse effects, and improved his behavioral problem. The treatment with lidocaine followed by mexiletine was useful for controlling clusters of intractable seizures.

Proton magnetic resonance spectroscopy to study the metabolic changes in the brain of a patient with Leigh syndrome

Localized proton magnetic resonance spectroscopy (MRS) was performed to study the metabolic changes in the brain of a patient with Leigh syndrome, who had a T-->G point mutation at nt 8993 of mitochondrial DNA. In this patient, sodium dichloroacetate therapy normalized the lactate and pyruvate levels in both blood and cerebrospinal fluid (CSF). However, his psychomotor retardation did not improve and magnetic resonance imaging showed progressive cerebral atrophy. In the patient's spectra, elevation of brain lactate was observed throughout the brain with regional variations, predominantly in the basal ganglia and brainstem with an abnormal MRI appearance. Although the lactate/creatine ratio observed on proton-MRS was related to the CSF lactate level, the ratio did not completely parallel the CSF lactate level, i.e. brain lactate was detected even when the CSF lactate level had become normalized. Furthermore, proton-MRS revealed a decrease in the N-acetylaspartate/creatine ratio and an increase in the choline/creatine ratio, representing neuronal loss and breakdown of membrane phospholipids. The clinical and MRI findings were well related to the changes in spectroscopically determined brain metabolites. These results indicate that the brain metabolites observed on proton-MRS are useful indicators of a response to therapy and prognosis in Leigh syndrome.

Beta-2-microglobulin and ferritin in cerebrospinal fluid for evaluation of patients with meningitis of different etiologies

To determine whether or not the beta-2-microglobulin (beta2-m) and/or ferritin levels in cerebrospinal fluid (CSF) can be used as markers for the differential diagnosis of meningitis and determination of the response to treatment, 122 subjects with etiologically well-characterized diagnoses were classified into three groups: bacterial meningitis (n = 5; mean age +/- SD. 1.0+/-1.0 year), viral meningitis (n = 39; 5.9+/-3.8 years), and a non-meningitis group (n = 78; 5.2+/-4.9 years). The levels of beta2-m and ferritin in CSF were determined by means of a latex photometric immunoassay. The statistical significance of the data was analyzed with the Mann Whitney U-test. A receiver operating characteristic curve was used to evaluate the diagnostic accuracy of each prediction marker. This study indicated that (1) the levels of beta2-m and ferritin in CSF were related with age in the non-meningitis group: subjects of up to 5 months of age exhibited higher concentrations of these proteins than ones of above 6 months of age (beta2-m, 1.89+/-1.13 vs. 0.84+/-0.65 mg/l. P < 0.01; ferritin, 2.97+/-2.04 vs. 1.81+/-1.34 microg/l, P = 0.09); (2) the beta2-m level was significantly higher in the CSF of patients with viral meningitis than in ones without meningitis (2.41+/-1.23 vs. 0.84+/-0.65 mg/l, P < 0.01): the best cut-off value was 1.2 mg/l (3) the ferritin level was significantly higher in the CSF of patients with bacterial meningitis than in ones with viral meningitis (43.24+/-39.49 vs. 6.81+/-7.41 microg/l, P < (.01): the best cut-off value was 7.5 microg/l; and (4) sequential measurement of the CSF ferritin level was of value for determination of the response to antibiotic treatment for bacterial meningitis. These results only apply to patients of greater than 6 months of age. beta2-m and ferritin in the CSF can be used as an ancillary tool for diagnostic guidance in the acute phase of meningitis and determination of the response to treatment for bacterial meningitis.

Encephalopathy associated with haemophagocytic lymphohistiocytosis following rotavirus infection

A 2-year-old Japanese boy with a haemophagocytic lymphohistiocytosis (HLH) associated encephalopathy which developed after rotavirus infection is described. The neurological symptoms consisted of coma, seizures and spastic quadriplegia. On therapy with steroids, etoposide and cyclosporin A, the patient recovered without any neurological deficits. The interferon-gamma levels in serum and CSF were elevated at onset of the disease but had returned to normal at the time of clinical remission. Brain MRI revealed diffuse white matter abnormalities and parenchymal volume loss. Proton magnetic resonance spectroscopy revealed elevated lactate in the abnormal lesions observed on MRI, indicating that macrophages not exhibiting aerobic metabolism had infiltrated the CNS. At the time of clinical remission, the white matter abnormalities and brain lactate had disappeared. These findings suggested that the neurological symptoms resulted from the overproduction of cytokines by activated T-cells and macrophages. The pathophysiology of a HLH associated encephalopathy was considered to be a local immune response within the CNS, because interferon-gamma can induce the expression of major histocompatibility complex class I and II antigens on glial cells in the CNS.

CONCLUSION

Haemophagocytic lymphohistiocytosis associated encephalopathy should be considered early in the differential diagnosis of cases with acute onset neuropathy.

Blood-brain barrier glucose transporter: effects of hypo- and hyperglycemia revisited

The transport of glucose across the blood-brain barrier (BBB) is mediated by the high molecular mass (55-kDa) isoform of the GLUT1 glucose transporter protein. In this study we have utilized the tritiated, impermeant photolabel 2-N-[4-(1 -azi-2,2,2-trifluoroethyl)[2-3H]propyl]-1,3-bis(D-mannose-4-ylo xy)-2-propylamine to develop a technique to specifically measure the concentration of GLUT1 glucose transporters on the luminal surface of the endothelial cells of the BBB. We have combined this methodology with measurements of BBB glucose transport and immunoblot analysis of isolated brain microvessels for labeled luminal GLUT1 and total GLUT1 to reevaluate the effects of chronic hypoglycemia and diabetic hyperglycemia on transendothelial glucose transport in the rat. Hypoglycemia was induced with continuous-release insulin pellets (6 U/day) for a 12- to 14-day duration; diabetes was induced by streptozotocin (65 mg/kg i.p.) for a 14- to 21-day duration. Hypoglycemia resulted in 25-45% increases in regional BBB permeability-surface area (PA) values for D-[14C]glucose uptake, when measured at identical glucose concentration using the in situ brain perfusion technique. Similarly, there was a 23+/-4% increase in total GLUT1/mg of microvessel protein and a 52+/-13% increase in luminal GLUT1 in hypoglycemic animals, suggesting that both increased GLUT1 synthesis and a redistribution to favor luminal transporters account for the enhanced uptake. A corresponding (twofold) increase in cortical GLUT1 mRNA was observed by in situ hybridization. In contrast, no significant changes were observed in regional brain glucose uptake PA, total microvessel 55-kDa GLUT1, or luminal GLUT1 concentrations in hyperglycemic rats. There was, however, a 30-40% increase in total cortical GLUT1 mRNA expression, with a 96% increase in the microvessels. Neither condition altered the levels of GLUT3 mRNA or protein expression. These results show that hypoglycemia, but not hyperglycemia, alters glucose transport activity at the BBB and that these changes in transport activity result from both an overall increase in total BBB GLUT1 and an increased transporter concentration at the luminal surface.

Cognitive deterioration associated with focal cortical dysplasia

Surgery for an area of focal cortical dysplasia in a critical region is reported in a right-handed female manifesting intractable focal epilepsy and verbal cognitive deterioration. She developed the first seizure at 2 years of age and was treated with phenytoin and zonisamide, with good control until 10 years of age. Although seizures did not occur at 9 years of age, she manifested dyscalculia, right-left disorientation, and finger agnosia, and N-isopropyl-p-iodoamphetamine single-photon emission computed tomography (SPECT) revealed focal hypoperfusion in the left parietal lobe. At 11 years of age, she developed regular nocturnal seizures and gradually lost the ability to understand the meaning of sentences. Verbal IQ declined from 94 to 63, and the area of hypoperfusion detected by interictal N-isopropyl-p-iodoamphetamine SPECT spread over the left parietotemporal lobes. Magnetic resonance imaging revealed focal cortical dysplasia mainly in the left parietal lobe, and ictal technetium-99m-ethyl cysteinate dimer SPECT images demonstrated an area of hyperperfusion around the focal cortical dysplasia, including the left precentral gyrus. Because of the overlap between the epileptogenic and functional cortex, the authors concluded that cortical resection, including focal cortical dysplasia, was inappropriate in this patient.

Serum melatonin kinetics and long-term melatonin treatment for sleep disorders in Rett syndrome

We studied the circadian rhythm of serum melatonin levels in two patients with classical Rett syndrome having severe sleep disorders; serum melatonin levels were measured before and during melatonin treatment using radioimmunoassay. Patient 1 had a free-running rhythm of sleep-wake cycle from 3 years of age. At the age of 4 years, the peak time of melatonin was delayed 6 h compared to normal control and the peak value was at the lower limit. Patient 2 had a fragmented sleep pattern accompanied by night screaming from 1 year and 6 months of age. At the age of 10 years, the peak time of melatonin secretion was normal but the peak value was at the lower limit. These patients were given 5 mg melatonin orally prior to bedtime. Exogenous melatonin dramatically improved the sleep-wake cycle in patient 1. In patient 2, exogenous melatonin showed a hypnotic effect but early morning awakenings occurred occasionally. When melatonin treatment was stopped, the sleep disorders recurred and re-administration of 3 mg melatonin was effective in both patients. The effect was maintained over 2 years without any adverse effects. These findings suggests that sleep disorders in patients with Rett syndrome may relate with an impaired secretion of melatonin.

Distinct regulation of myoblast differentiation by intracellular and extracellular fibroblast growth factor-1

We studied the role of fibroblast growth factor (FGF)-1 in the physiology of myoblast differentiation. We found that, while endogenous FGF-1 in L6-10 rat myoblasts did not suppress the progress of differentiation, the addition of FGF-1 to the culture medium suppressed it. Moreover, L6-10 cells stably transfected with full length FGF-1 undergo enhanced differentiation. The latter was well correlated with myogenin expression and myotube formation. Constitutive expression of a mutant FGF-1 (FGF-1U) that lacked a nuclear localization signal, promoted the differentiation of the myoblasts even more strongly. Furthermore, the expression of FGF-1U in an inducible expression system enhanced myogenin expression promptly. In L6-10 transfectants expressing a dominant-negative mutant of FGF receptor, stable transfection of FGF-1 promoted differentiation as it did in parent cells. Studies with FGF receptors and MAP kinase suggest that both are involved in the effect of FGF-1 when it is supplemented to culture medium but not during the effect of endogenous FGF-1 synthesized in cells. We conclude that intracellular (endogenous) and extracellular (exogenous) FGF-1 have differential effects on the regulation of myogenic differentiation of L6-10 cells.

Effects of neonatal hypoxia on the medulla-spinal cord descending neurons

Hypoxic changes in the medulla-spinal cord descending neurons were studied morphologically using a retrograde neurotracer, choleratoxin B subunit (CTb). On postnatal day 7, Sprague-Dawley rats were subjected to a hypoxic load of 8% oxygen for 5 hours. In the rats that survived, CTb was injected into the lumbar enlargement at postnatal day 26, and they were killed at postnatal day 28 for histologic analysis. Retrograde transported CTb was visualized by immunohistochemistry. The results were compared with those obtained from control rats. In the control rats, CTb-positive cells were observed in the nucleus reticularis gigantocellularis, nucleus reticularis magnocellularis, nucleus raphe magnus, nucleus raphe obscurus, and nucleus raphe pallidus. In the hypoxic rats, although CTb-positive cells were detected in the same areas as the control rats, there was a noteworthy decrease in the number of CTb-positive cells in all areas, and there were many cells with hypoxic degeneration. In all of the nuclei a marked decrease in the number of CTb-positive cells was observed. Because medulla-spinal cord descending neurons have important roles in the regulation of postural muscle tone, these results may account for the pathophysiology of abnormal muscle tonus accompanying hypoxic brain damage.

Cyclic vomiting and elevation of creatine kinase associated with bitemporal hypoperfusion and EEG abnormalities: a migraine equivalent?

A 13-year-old mentally retarded boy suffered from repeated vomiting attacks since infancy. Each episode lasted 2 to 10 days, and was precipitated by respiratory infection, exercise or stress. During an attack he became irritated, agitated and amnesic, but did not have headaches or seizures. Associated findings were transient elevation of serum creatine kinase (CK) (331-3381 IU/l), and of plasma ACTH and cortisol. The raised CK level was the result of muscle hypertonicity. Ictal EEGs showed delta activity in the front-temporal areas, and inter-ictal IMP-SPECT revealed hypoperfusion in both temporal regions. Unlike the periodic ACTH-ADH discharge syndrome, neither hypertension nor depression developed. These attacks were diagnosed as a migraine equivalent and were suppressed with phenytoin. From the EEG and SPECT findings, we concluded that the vomiting and behavioural changes were related to the paroxysmal vascular abnormality in the temporal regions, but it was not easy to make the distinction between migraine and focal epilepsy. Before a diagnosis of the periodic ACTH-ADH discharge syndrome is made, the possibility of migraine equivalent should be considered.

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.

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.

[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.

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.

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.

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

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.

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.

CTG trinucleotide repeat length and clinical expression in a family with myotonic dystrophy

Unstable expansion of the CTG repeats in the 3' untranslated region encoding a member of the protein kinase family in the q13.3 band on chromosome 19 is a mutation specific for myotonic dystrophy. To examine the correlation between clinical expression and CTG trinucleotide repeat length, we carried out Southern blot analysis in a family with myotonic dystrophy. In this pedigree, the expanded CTG repeats were transmitted maternally. The mother had three female children. The mother had about 200 CTG repeats, and the number of repeats for each child was about 800, 1500 and 1600 in birth order. The mother and the patient with 800 repeats were unaware of muscle weakness or myotonia. Symptoms were present from age 3 years in the patient with 1500 repeats and from birth in the one with 1600 repeats. Although the mother menstruated regularly, the patients with 800 and 1500 repeats both menstruated irregularly, and the one with 1600 repeats has never menstruated. The age of onset and severity of the disease were correlated with the size of the expanded repeats. Endocrinological studies revealed that the basal levels of the gonadotropins, PRL and E2 were within normal range, and a pituitary response to LHRH was observed. These data suggest that the amenorrhea and menstrual irregularities were caused by a suprahypophyseal dysfunction. When expanded CTG repeats are transmitted maternally, abnormal products resulting from the metabolic disturbance in the affected mother may harm the fetus in utero. A heterozygous fetus, who has more CTG repeats, may be unable to metabolize the pathologic products sufficiently and therefore may become more severely affected. This may explain the exclusive maternal transmission of congenital myotonic dystrophy.

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.

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.

Serial neuroimages of acute necrotizing encephalopathy associated with human herpesvirus 6 infection

A previously healthy 8-month-old girl developed exanthem subitum and acute encephalopathy with status epilepticus, quadriplegia and bilateral abducens nerve palsies. Human herpesvirus-6 DNA was found in the cerebrospinal fluid by the polymerase chain reaction at the acute stage. Cranial computed tomography showed low density areas in the thalami and in the cerebellar and abducens nuclei. The distribution of the lesions was consistent with acute necrotizing encephalopathy. As for the thalamic lesions, a T2 weighted magnetic resonance image on the 24th day of the illness demonstrated low signal intensity surrounded by high intensity; 99mTc-ECD SPECT showed hypoperfusion, which suggested irreversible tissue damage. The patient is now 1 year 6 months old and has spastic quadriparesis with mental retardation and abducens nerve palsies.

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.

Effects of neonatal hypoxia on brainstem cholinergic neurons-pedunculopontine nucleus and laterodorsal tegmental nucleus

Hypoxic changes in the cholinergic neurons of the pedunculopontine nucleus (PPN) and the laterodorsal tegmental nucleus (LDT) were studied morphologically using immunohistochemistry for choline acetyltransferase (ChAT). Fifty-three postnatal day (PND) 7 Sprague-Dawley rats were subjected to a hypoxic load of 8% oxygen for 5 h. The rats which survived were later sacrificed at PND 14 or 28 for histological analysis. The results were compared with those obtained from control rats. Three weeks after hypoxic load, a decrease in the number of ChAT immunoreactive cells, especially in the caudal PPN, was found, although no remarkable changes were detected in cell morphology. Since several studies support the possibility that the cholinergic system from PPN/LDT is responsible for both REM generation and the general motor inhibition during REM sleep, our results may account, in part, for the clinical features of hypoxic brain damage such as sleep disorders and abnormal muscle tonus.

[Higher cortical dysfunctions and image diagnosis in a 9-year-old girl with complex partial epilepsy caused by focal neural migration disorder]

A 9-year-old right-handed girl was admitted because of complex partial seizures, left-right disorientation and finger agnosia. At the age of 2 years, she began to have seizures, which were exacerbated by carbamazepine and diazepam. Subsequently she was treated with phenytoin and phenobarbital, and remained seizure-free for four years. After age 7, she began to have attacks of alteration of consciousness, which lasted 10 seconds and occurred every two or three months. At age 9, neuropsychological testing revealed borderline intellectual functioning (WISC-R:FSIQ 83, VIQ 94, PIQ 73), but selective deficits were found in tests of calculation and spatial-figural relationships. Axial spin echo (3,000/22) image showed an abnormal high signal intensity in the left temporo-parieto-occipital lobe, in which interictal IMP-SPECT demonstrated decreased cerebral blood flow. These results seemed to explain the relationship between clinical findings and focal migration disorder. It is important to detect a focal migration disorder in patients with intractable focal epilepsy or higher cortical dysfunctions.

Acute transverse myelitis caused by ECHO virus type 18 infection

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.

[Exacerbation of seizures by carbamazepine in four children with symptomatic localization related epilepsy]

We treated one hundred and seventy-eight epileptic children with carbamazepine (CBZ) for eight years. Among them, four children with symptomatic localization-related epilepsy, aged 11 months to 12 years, developed exacerbation of seizures. Their epilepsies were associated with hypoxic ischemic encephalopathy, head injury and ectopic gray matter. Despite the serum levels of CBZ (7.0 approximately 9.5 micrograms/ml) being within the therapeutic range, all of them had more frequent and severe partial seizures than before taking CBZ and one developed new atonic seizures. Diffuse irregular spike-wave complexes appeared on EEG in two children. Following discontinuation of CBZ in addition to replacement with phenytoin, their seizures became well-controlled and EEG findings improved except for residual focal spikes. Although CBZ is a widely used and effective antiepileptic drug for partial seizures, it should be kept in mind that CBZ may exacerbate seizures in children with symptomatic localization-related epilepsy.

Theophylline-induced seizures in a 6-month-old girl. Serum and cerebrospinal fluid levels

The case is presented of a 6-month-old girl with theophylline-induced focal seizures associated with tachycardia, tremor and irritability. The serum level of theophylline was 20.0 micrograms/ml 30 min after the onset of seizures, and declined to half this level at 19 h. The ratio of the concentration in cerebrospinal fluid (CSF; 8.9 micrograms/ml) to serum (16.4 micrograms/ml) was 0.54 at 4.5 h after the onset. Despite the cessation of seizures, the EEG showed periodic high voltage delta waves over the right hemisphere and left-sided flatness. Since theophylline diffuses easily through the blood-brain barrier in infancy, serum levels should be maintained below 15 micrograms/ml unless severe bronchial asthma occurs.

[A longitudinal study of children with language delay at 3 years of age; later WPPSI and school attendance]

Ninety-four children (eighty-three boys and eleven girls), who were delayed in verbal expression (expressive language less than two-thirds of the standard for their chronological ages) at the age of three years, were evaluated for school attendance and intelligence at the age of six. The Yamada's Check List for Language Development and Wechsler Preschool and Primary Scale of Intelligence (WPPSI) were used to assess language problems and the intelligence quotient (IQ). Thirty children (32%) were delayed in verbal expression only, and sixty-four (68%) were delayed in both: verbal expression and comprehension were less than two-thirds of the standard for their chronological ages. Of children with delay in verbal expression only, 36% of them had low full-scale IQs (less than 70), and 27% had required special tutoring. Of children with delayed development of verbal expression and comprehension, 85% had low full-scale IQs, and 89% had required special tutoring or had attended schools for mentally retarded children. In expressive and comprehensive language delay, forty-one children avoided personal relations at the age of three years. Later thirty of these children were diagnosed as suffering from infantile autism. Poor mental outcome could be predicted by the delay of expressive and comprehensive language at the age of three years. The high prevalence of developmental disorders at later stages for the children in this study suggests the need for close monitoring of children with delayed language.

[Exacerbation of partial seizures in a case with heterotopic gray matter using antiepileptic drugs]

A two-year-old, right-handed girl was admitted to our hospital with a history of partial seizures. The first seizure, conjugated eye movements and head turning to the right, occurred at the age of 24 months. Later, she suffered from several seizures daily at the age of 34 months. At the age of 35 months, she was admitted to our hospital. On admission her neurological examination was normal. EEG showed a left parietal spike focus. A computed tomographic scan showed a small hyperdense area in the left parietal lobe without contrast enhancement. She was treated with carbamazepine (CBZ : 6 mg/kg/day). When seizures occurred several times within an hour, intravenous or rectal administration of diazepam (DZP : 0.3 mg/kg/dose) was added. However, she complained of sleepiness. The seizures occurred more frequently than before, 50 to 80 times daily, and became secondarily generalized. We thought that the exacerbation of the seizures resulted from the somnolence caused by DZP and CBZ. Consequently, these drugs were discontinued, and phenytoin was begun. She has since been free of seizures for two years. Approximately one year after the discontinuance of DZP and CBZ, heterotopic gray matter and abnormal gyri involving the left parieto-temporal lobe were found by magnetic resonance imaging (MRI). MRI is useful for detecting small heterotopic gray matter. To summarize this case, one should consider the possibility that excessive polytherapy induces seizures, particularly in patients with structural brain abnormalities such as heterotopic gray matter.

[A case of Menkes' kinky hair disease with a renal calculus and diverticula of the bladder]

Menkes' kinky hair disease is a poor prognostic congenital disease with X-linked recessive inheritance. This disease is clinically characterized by seizures, friable hair, growth failure, mental retardation and others. Recently it has been known that this disease is also characterized by multiple diverticula of the bladder and other urological abnormalities. A 6-year-old boy was diagnosed as having Menkes' kinky hair disease at another hospital several weeks after birth because of seizures, friable hair and low serum copper level. He voided by Credé's maneuver by the nurse because he could not void for himself. He was referred to our hospital for macrohematuria and micturition pain on October 8, 1989. Right renal staghorn calculus and multiple diverticula of the bladder were found by roentgenographic examination. He has been treated conservatively after discharge because of his poor condition.

Pharmacological activities of the prenylcoumarins, developed from folk usage as a medicine of Peucedanum japonicum THUNB

In connection with the chemical structure of coumarin 1 (a mixture of acetylangeloylkhellactone and acetyltigloylkhellactone), a compound isolated from Peucedanum japonicum THUNB., we synthesized eight coumarin compounds (3-10) and performed pharmacological studies on these nine compounds, as well as on another coumarin, praeruptorin A (= Pd-Ia) (2), a compound isolated from Peucedanum praeruptorum DUNN. We studied the effects of compounds 1-5 on isolated smooth muscle and of compounds 1-10 on the cardiovascular system. These compounds showed dose-related antagonistic effects on histamine- and Ca(2+)-induced contractions in smooth muscle and the potencies were in the order 2 greater than 1 greater than seselin (3) greater than xanthyletin (4) = 2.2.10-trimethyl-2H,8H-benzo[1,2-b: 3,4-b']dipyran-8-one (5). All the compounds except 7-geranyloxy-4-methylcoumarin (10) produced a dose-related increase in vertebral, carotid and femoral blood flow. Compounds 1, 5, and 4-methyl-7-(3-methyl-2-butenyloxy)coumarin (8) caused an increase in blood pressure, but 3 and 4 caused a slight decrease. Compounds 2, 3, 4, 5, and 8 increased heart rate. Jatamansinone (6) and jatamansinol (7) caused only slight changes in blood pressure. All the compounds except 10 increased heart rate. Compound 1 also increased blood flow in the cerebral cortex. Thus, compound 1 was confirmed to have an inhibitory effect on contraction in isolated smooth muscle and an action increasing arterial blood flow. Among the compounds tested in this study, 3, as well as 6 and 7 synthesized on the basis of 3, showed actions similar to those of Ca2+ blockers and some compounds had papaverine-like activities.(ABSTRACT TRUNCATED AT 250 WORDS)

Hypocalcemic focal seizures in a one-month-old infant of a mother with a low circulating level of vitamin D

We present a case of a one-month-old infant with hypocalcemia and rickets, with symptoms of focal seizures. The ictal EEG showed left occipital spikes spreading over all of the left hemisphere. From the laboratory studies, we concluded that a low maternal circulating level of vitamin D would cause infantile hypocalcemia and rickets, while immature renal response to parathyroid hormone and transient hypoparathyroidism in infancy would induce hyperphosphatemia. Hypocalcemia may be an important factor in the cause of focal seizures which start even after the age of one month. Further, investigation of maternal vitamin D levels should be done in infantile hypocalcemia.