Transient antiphospholipid antibodies associated with acute infections in children: a report of three cases and a review of the literature

We describe two previously healthy children who had multiple ecchymoses several days after acute infection. In both cases, the prothrombin time (PT) and the activated partial thromboplastin time (APTT) were prolonged. Further examinations revealed the presence of lupus anticoagulant (LA), phosphatidylserine-dependent antiprothrombin antibodies (aPS/PT), and low serum complement. In both cases, we confirmed the presence of a serum immune complex. The patients' symptoms improved spontaneously within 1 week, and all laboratory data normalized within several months. We also describe another asymptomatic case positive for LA and aPS/PT presumably associated with cytomegalovirus infection. The prevalence of transient antiphospholipid antibodies associated with viral infections in children must be much higher than we expected. We have to take it into consideration when we see abnormal coagulation results, but the occurrence of significant bleeding symptoms is rare.

Chromosomal mapping of genes for epilepsy in NER: a rat strain with tonic-clonic seizures

PURPOSE

NER is a mutant rat strain that exhibits spontaneous tonic-clonic convulsions accompanied by epileptic discharges on ictal EEG and serves as a model for generalized tonic-clonic seizures in humans. Our previous experiments have suggested that a major autosomal recessive gene and several minor genes regulate the inheritance of tonic-clonic seizures in NER. The purpose of this study was to confirm the mode of inheritance and to locate the causative genes for epilepsy in NER on the rat genetic map.

METHODS

We developed F1 hybrid (F1) and reciprocal back-cross progenies of NER with a seizure-resistant strain, F344, and evaluated their seizure susceptibility under tossing-stimulated and nonstimulated conditions. Backcross animals were genotyped using simple sequence length polymorphism markers for polymerase chain reactions. Linkage between seizure susceptibility and marker loci was analyzed by chi2 statistic tests and by the computer programs MAPMAKER/EXP and MAPMAKER/QTL.

RESULTS

Under tossing-stimulating conditions, tonic-clonic seizures were provoked in 90% of NER and 66% of (F1 x NER) backcross animals, but no seizures occurred in the F344, F1, or (F1 x F344) backcross animals. Routine monitoring of nonstimulated animals revealed spontaneous tonic-clonic convulsions in 100% of NER and 64.2% of (F1 x NER) backcross animals, but no seizures in F344 or F1. Gender effect on seizure susceptibility was negligible in (F1 x NER) backcross in both conditions. Preliminary genome-wide scanning and subsequent precise location of the causative genes revealed seizure susceptibility loci, designated Ner1 and Ner2, on rat chromosomes 1 and 3, respectively.

CONCLUSIONS

Ner1 is a locus that controls the inheritance of spontaneous tonic-clonic seizures in an autosomal recessive mode, whereas Ner2 affects the occurrence of tossing-induced seizures. Orthologous genes in the vicinity of these loci may be related to epileptogenesis in other species, including humans.

Accumulation of N-acetyl-L-aspartate in the brain of the tremor rat, a mutant exhibiting absence-like seizure and spongiform degeneration in the central nervous system

The tremor rat is a mutant that exhibits absence-like seizure and spongiform degeneration in the CNS. By positional cloning, a genomic deletion was found within the critical region in which the aspartoacylase gene is located. Accordingly, no aspartoacylase expression was detected in any of the tissues examined, and abnormal accumulation of N-acetyl-L-aspartate (NAA) was shown in the mutant brain, in correlation with the severity of the vacuole formation. Therefore, the tremor rat may be regarded as a suitable animal model of human Canavan disease, characterized by spongy leukodystrophy that is caused by aspartoacylase deficiency. Interestingly, direct injection of NAA into normal rat cerebroventricle induced 4- to 10-Hz polyspikes or spikewave-like complexes in cortical and hippocampal EEG, concomitantly with behavior characterized by sudden immobility and staring. These results suggested that accumulated NAA in the CNS would induce neuroexcitation and neurodegeneration directly or indirectly.

Structure and NIR feature of QCC: a laboratory analog of carbon dust

We have produced thin films of quenched carbonaceous composite (QCC) by hydrocarbon plasma deposition. The effect of thermal annealing on QCC has been investigated to understand how QCC, as a laboratory analog of carbon dust, is transformed in the warm environment around evolved stars. Spectroscopic measurements have indicated that, by heating, the proportion of aromatic sp2 CH bonds increases relative to sp3 CH bonds. Carbon onion-like spherules of approximately 10 nm in diameter are found with electron microscopic images after "graphitization" of thermal annealing.

Benign familial neonatal convulsions followed by benign epilepsy with centrotemporal spikes in two siblings

PURPOSE

To report on sibling cases with benign familial neonatal convulsions (BFNC) followed by benign epilepsy with centrotemporal spikes (BECT).

METHODS

Case histories and EEGs were obtained for the two siblings with neonatal and subsequent epileptic seizures in one pedigree with BFNC.

RESULTS

The family included six affected cases of BFNC in two generations: the proband, the proband's mother and two sisters, and the proband's maternal uncle and his daughter. The proband developed a generalized tonic convulsion 2 days after birth with no apparent cause and normal interictal EEG, and experienced a total of 18 episodes of tonic or clonic seizures or both by age 9 months. In the follow-up course, an EEG recording showed rolandic discharges at 2 years, and a sylvian seizure occurred at 4 years during sleep. On carbamazepine therapy, the last seizure was recorded at 9 years after a total of 11 episodes of sylvian seizures, with normal EEGs after 12 years. The proband's sister experienced nine episodes of brief tonic seizures between 7 and 9 days after birth, and also developed eight episodes of sylvian seizures from 4 to 7 years, with rolandic discharges on EEG until age 9 years. All of the family members had normal psychomotor development, with no neurologic sequelae.

CONCLUSIONS

This report of BFNC followed by BECT in sibling cases is significant in view of the genetic analysis and the classification of epilepsies and epileptic syndromes.

Cockayne syndrome without typical clinical manifestations including neurologic abnormalities

Although patients with mild symptoms of atypical Cockayne syndrome (CS) have been described, there has not been a report of a patient with CS whose only clinical manifestation was cutaneous photosensitivity. Cells from patients with CS show UV sensitivity, reduced recovery of RNA synthesis, but normal UV-induced unscheduled DNA synthesis. On the other hand, the patients with UV-sensitive syndrome have only cutaneous photosensitivity and skin freckles, whereas those cells respond to UV radiation in a similar fashion to the CS cells. We describe a patient with CS who showed only photosensitivity without typical clinical manifestations of CS, but his cells showed UV sensitivity, reduced recovery of RNA synthesis, and normal unscheduled DNA synthesis after UV radiation similar to CS cells. Furthermore, the patient was assigned to complementation group B of CS on the basis of the results of complementation analysis. The present report suggests that CS has a wider spectrum than that considered previously.

Correlation between genetic and cytogenetic maps of the rat

To correlate rat genetic linkage maps with cytogenetic maps, we localized 25 new cosmid-derived simple sequence length polymorphism (SSLP) markers and 14 existing genetic markers on cytogenetic bands of chromosomes, using fluorescence in situ hybridization (FISH). Next, a total of 58 anchor loci, consisting of the 39 new and 19 previously reported ones, were integrated into the genetic linkage maps. Since most of the new anchor loci were developed to be localized near the terminals of the genetic or cytogenetic maps for each chromosome, the orientation and coverage of the whole genetic linkage maps were determined or confirmed with respect to the cytogenetic maps. Thus, we provide here a new base for rat genetic maps.

NER rat strain: a new type of genetic model in epilepsy research

PURPOSE

We characterized and evaluated as an animal model of epilepsy NER, a new epileptic rat strain, which was developed by inbreeding rats with spontaneous tonic-clonic seizures in a stock of Crj:Wistar.

METHODS

Animals were monitored through the inbreeding course, and video-EEGs were recorded selectively. External seizure-provoking stimuli were applied to NER and to a control parental strain. F1, F2, and backcross progenies were produced between NER and a nonepileptic unrelated strain. Pathologic study included hematoxylin-and-eosin (HE), Klüver-Barrera's, modified Bodian silver, and neo-Timm's staining.

RESULTS

After the F9 generation, 94%-98% of NER exhibited spontaneous tonic-clonic convulsions, beginning with neck and forelimb clonus, wild jumping/running, opisthotonic posturing, and evolving to tonic, then clonic convulsion, followed by postictal flaccidity. Most seizure onsets occurred between 2-4 months of age, and the incidence was 0.45 +/- 0.21 seizures in 12 h. Ictal cortical and hippocampal EEGs were characterized by high-voltage spikes followed by diffuse spike-and-wave or polyspike-and-wave complexes. NER revealed seizure susceptibility to pentylenetetrazol, tossing, and transcorneal electroshock, but not to tactile, photic, or acoustic stimuli, or to transauricular electroshock. Mating experiments revealed that 0% (0/46) of the animals in F1, 25.5% (13/51) in F2, and 63.6% (56/88) in backcross progenies exhibited spontaneous tonic-clonic convulsions without sex difference. For all these epileptic traits, no pathologic changes were demonstrated in the CNS.

CONCLUSIONS

NER frequently exhibited spontaneous convulsions, controlled by a major autosomal recessive gene for epilepsy, that are comparable to generalized tonic-clonic seizures in humans. This can serve as a new genetic model in epilepsy research.

[18F]-fluorodeoxyglucose-positron emission tomography findings in protein infants with severe periventricular leukomalacia and hypsarrhythmia

Two preterm infants with extensive periventricular leukomalacia (PVL) were examined by [18F]-fluorodeoxyglucose-positron emission tomography (FDG-PET) at the corrected ages of 18 and 34 days. They showed similar clinical courses including oculoclonic seizure, hypsarrhythmia and severe mental retardation, in addition, to spastic quadriplegia. FDG-PET study of these two infants with severe PVL disclosed poorly developed metabolic activity in the primary sensorimotor cortex, while the MRI images displayed only periventricular white matter lesions.

CONCLUSIONS

Positron emission tomography may disclose cortical involvement in infants with severe periventricular leukomalacia.

Congenital bilateral perisylvian syndrome: first report in a Japanese patient

A Japanese boy with congenital bilateral perisylvian syndrome is described. He had oropharyngoglossal dysfunction and severe dysarthria. Magnetic resonance imaging of the brain disclosed bilateral perisylvian malformations suggesting polymicrogyria. The patient also showed mental retardation, epilepsy, and poor motor skills.

Gene mapping of NMDA receptors and metabotropic glutamate receptors in the rat (Rattus norvegicus)

Five N-methyl-D-aspartate receptor subunit genes and six metabotropic glutamate receptor subtype genes have been assigned to particular rat chromosomes by using a rat x mouse somatic cell hybrid clone panel. N-Methyl-D-aspartate receptor subunit genes (gene symbol, GRIN) GRIN1, GRIN2A, GRIN2B, GRIN2C, and GRIN2D have been assigned to chromosomes (Chr) 3, 10, 4, 10, and 1, respectively. Metabotropic glutamate receptor subtype genes (gene symbol, GRM) GRM1, GRM2, GRM3, GRM4, GRM5, and GRM6 have been assigned to Chr 1, 8, 4, 20, 1, and 10, respectively. In addition, GRIN2A and GRM6 loci were successfully localized on Chr 10 linkage maps by linkage analyses. The genetic distances between loci in cM (+/- SD) are as follows: GRIN2A-28.6(+/- 7.0)-RR24-23.3(+/- 6.4)-MYHSE, from a linkage analysis using the (SHR x WTC)F1 x WTC cross, and RR24-4.2(+/- 2.9)-GRM6-4.2(+/- 2.9)-MMYHSE-2.1(+/- 2.1)-ASGR, SHBG-27.1(+/- 6.4)-PPY, from a linkage analysis using the (ZI x TM)F1 x ZI cross.

Phenytoin reduces neonatal hypoxic-ischemic brain damage in rats

We investigated the possible protective effect of phenytoin on hypoxic-ischemic brain damage in neonatal rats. Six-day-old rats underwent ligation of the left carotid artery followed by exposure to an 8% oxygen atmosphere for 2.5 hrs. We sacrificed the animals 72 hrs later and assessed the hypoxic-ischemic brain damage histologically. Phenytoin (50 mg/kg), administered intraperitoneally 1 hr before the hypoxia, reduced hypoxic-ischemic infarction in the cerebral cortex and striatum, and attenuated neuronal necrosis in the hippocampus. The plasma concentration of phenytoin after injection was 11.1 +/- 1.9 micrograms/ml (mean +/- S.E.M.) at 1 hr and 22.9 +/- 1.4 micrograms/ml at 4 hrs. Percent volumes of the infarction calculated by dividing the sum of damaged areas by the total area in serial coronal sections were 79 +/- 3% (mean +/- S.E.M.) in vehicle controls versus 13 +/- 6% in phenytoin-treated pups in the cerebral cortex, and 79 +/- 4% in vehicle controls versus 12 +/- 5% in phenytoin-treated pups in the striatum. We semiquantitatively investigated the hypoxic-ischemic change in 5 hippocampal areas: dentate gyrus, CA4, CA3, CA1, and subiculum, in the dorsal hippocampus. Pre-hypoxic treatment with phenytoin reduced hypoxic-ischemic damage in all areas examined. When phenytoin was administered immediately after the hypoxia, there was no difference between vehicle-injected controls and phenytoin-treated pups. These results demonstrate that phenytoin can reduce neonatal hypoxic-ischemic brain damage.