Keiichi Morooka

Determination of Serotypes of Astroviruses by Reverse Transcription‐Polymerase Chain Reaction and Homologies of the Types by the Sequencing of Japanese Isolates

Human standard astroviruses, serotypes 1 to 7, and 35 Japanese isolates were typed by reverse transcription and polymerase chain reaction (RT‐PCR) with serotype‐specific primers for the first time. The results were identical with those obtained by enzyme immunoassay with serotype‐specific polyclonal antibodies, a method which has already been reported. RT‐PCR with serotype‐specific primers is useful for epidemiological studies of astroviruses where serotype‐specific polyclonal antibodies are not available. Two parts of the capsid region, N terminus and C terminus, were sequenced. Serotypes differed in those regions. The N terminus differed less than the C terminus between serotypes. Both the N terminus and C terminus were similar intraserotypically with the exception of serotype‐4 isolates which could be divided into A and B subgroups on the basis of their C terminus sequences, which were not known previously.

Clinical Effects of Allopurinol on Intractable Epilepsy

Summary: We studied the clinical efficacy of allopurinol as add‐on therapy in 31 patients with intractable epilepsy. When administered for a short time, allopurinol was effective in 17 patients (55%); 8 were seizure‐free, 8 had 75% decrease in seizure frequency, and 1 had >50% decrease. Allopurinol was most effective in patients with localization‐related epilepsy, especially in secondarily generalized tonic‐clonic seizures. Allopurinol was not as effective in patients with Lennox syndrome or West syndrome, or in severe myoclonic epilepsy in infants. When allopurinol was administered > 1 year, its initial effectiveness continued in 8 of 14 patients who exhibited initial improvement. In 2 of the remaining 6 patients, the initial improvement disappeared during the course of treatment but control was regained by increasing the dosage of allopurinol. Mild side effects were observed in 4 patients (13%): drowsiness in 3 and abdominal pain in 1. Allopurinol may be a useful antiepileptic drug (AED), and a double‐blind placebo‐controlled trial should be performed.

Study of the Maturation of the Child’s Brain Using 31P-MRS

The maturation of human cerebrum and cerebellum in 37 normal children aged 4 months to 13 years 8 months was evaluated by 31P-magnetic resonance spectroscopy using two different conditions of repetition time (TR) (TR = 3 seconds and 15 seconds) in each region. The results were as follows. First, the PME/PDE, PCr/gamma-ATP and Pi/PCr ratios differed between the cerebrum and the cerebellum. The PME/PDE and PCr/gamma-ATP ratios were greater in the cerebellum than in the cerebrum. However, the Pi/PCr ratio was smaller in the cerebellum than in the cerebrum. At TR = 3 seconds, the ratio of (PME/PDE ratio in the cerebellum)/(PME/PDE ratio in the cerebrum) and the ratio of (PCr/gamma-ATP ratio in the cerebellum)/(PCr/gamma-ATP ratio in the cerebrum) manifested a nearly constant value independent of age. Second, the phosphomonoester peak in the cerebrum contained a substance with a longer relaxation time than 3 seconds; this substance was present in large amounts in the early period, then gradually decreased during maturation.

Genetic Variation in the Capsid Region of Human Astrovirus Serotype 4 Isolated in Japan

The entire capsid regions of 12 serotype‐4 astroviruses from Japan were sequenced and compared with those of other serotypes. Serotype‐4 isolates were divided into two new subgroups. The intrasubgroup nucleic acid and deduced amino acid sequences were quite homologous (more than 93%), but slightly less so between subgroups (almost 85%). However, the serotype‐4 sequences differed from those of serotypes 1,2,3,5,6,7 and 8 (less than 50%). Determining whether these differences significantly alter the epidemiology and antigenicity will require further investigation.

Antiepileptic effects of allopurinol involved in hippocampal specific SOD (superoxide dismutase) induction in the mutant El mouse.

Recently the xanthine oxidase inhibitor, allopurinol, has been clinically demonstrated to exert antiepileptic effects: particularly on secondarily generalized seizures.’ The El mouse is an epileptic mutant model of secondarily generalized seizure.6 Several lines of evidence indicate that in the El, the parietal cortex plays an important role in seizure initiation and the hippocampus plays a role in the generalization of se iz~res .~ And the developmental formation of the “Focus Complex” which is mainly constituted from the parietal cortex and hippocampus should be deeply involved in the epileptogene~is.~ Antiepileptic effects of allopurinol were determined in the El. Furthermore, the mode of action of allopurinol was investigated by measuring the activities of superoxide dismutase (SOD) according to the time course after the administration of allopurinol.