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Biomedical subjects

Kazuyoshi Morimoto

Publications and source records attributed to Kazuyoshi Morimoto.

13 recordsLinked to original sources

Neurodevelopmental outcome in children with posthemorrhagic hydrocephalus.

To determine the factors affecting the neurodevelopmental outcome in children with posthemorrhagic hydrocephalus, 78 children with intraventricular hemorrhage grade 3 or 4 were analyzed concerning the outcome in relation to the grade of intraventricular hemorrhage and intervention (surgical, medical, or no intervention) by means of a follow-up study. The mean age of the subjects at the last follow-up was 9.8 years. In children with intraventricular hemorrhage grade 4 with parenchymal hemorrhage, the outcomes in the group not requiring intervention were better than those in the groups requiring intervention, whereas in children with intraventricular hemorrhage grade 3 without parenchymal hemorrhage, there were no differences in the outcomes among the three groups with and without intervention. For the subjects who had undergone the same intervention, the outcomes in children with intraventricular hemorrhage grade 4 were worse than those in children with intraventricular hemorrhage grade 3. The outcomes in the children with surgical intervention only correlated with the grade of intraventricular hemorrhage. From these findings, we concluded that the outcomes in children with posthemorrhagic hydrocephalus were far more affected by the existence or extent of parenchymal hemorrhage than by the hydrocephalic process, which was suggested to be effectively controlled by the intervention.

Chi-Square Distribution↗

Inhibition of high K+-evoked gamma-aminobutyric acid release by sodium nitroprusside in rat hippocampus.

To clarify whether nitric oxide (NO) modifies high K(+)-evoked gamma-aminobutyric acid (GABA) release, we examined the effects of sodium nitroprusside, an NO donor; diethyldithiocarbamate, an NO trapper; dithiothreitol, a superoxide radical scavenger; and 1H-(1,2,4)oxadiazole(4,3-a)quinoxalin-1-one, a specific guanylyl cyclase inhibitor, on high (100 mM) K(+)-evoked GABA release from rat hippocampus in vivo using microdialysis. Perfusion with 0.5 or 5 mM sodium nitroprusside significantly reduced high K(+)-evoked GABA release. Co-perfusion with 0.5 mM sodium nitroprusside and 5 mM diethyldithiocarbamate or 0.5 mM 1H-(1,2,4)oxadiazole(4,3-a)quinoxalin-1-one significantly enhanced high K(+)-evoked GABA release. Co-perfusion with 0.5 mM sodium nitroprusside and 1 mM dithiothreitol tended to increase it. These results demonstrate that sodium nitroprusside reduces high K(+)-evoked GABA release both via an NO/cyclic GMP-dependent pathway and via an NO-dependent, but cyclic GMP-independent, pathway in rat hippocampus in vivo.

Animals↗

Quantitative follow-up analysis by computed tomographic imaging in neonatal hydrocephalus.

We sought a simple and accurate method to monitor neonatal hydrocephalic infants using standard computed tomographic scans. Volume measurements were made by means of pixel counting using a personal computer and a drawing device, as a graphic tablet system, over computed tomographic scans of six infants with neonatal hydrocephalus and four age-matched control infants. The mean value (763.9 +/- 83.3 cm(3)) of the volume of the cranium in the hydrocephalic group was two times higher than that in the age-matched control infants (360.4 +/- 41.4 cm(3)), P < 0.00001. Sequential changes of the ventricular/intracranial volume ratio steadily decreased after cerebrospinal fluid diversion by means of a "two-step procedure" as early in postnatal life as feasible. The mean value (0.67 +/- 0.12) of the lateral ventricle/intracranial volume ratio at birth improved to 12 months of age (0.26 +/- 0.14), P < 0.05. This study has documented, by means of quantitative analysis of serial scans, a statistically significant increase in the neonatal hydrocephalic brain volume after cerebrospinal fluid shunting.

Brain↗

Tethered cord associated with anorectal malformation.

Ten children with a tethered cord and also an anorectal malformation are reported in this document. The anorectal malformations comprised 5 vesicointestinal fissures, 2 cloacal exstrophies, 2 rectovesical fistulas and 1 rectobulbar fistula. All of the patients underwent colostomy in advance of surgery for untethering of the spinal cord. Although their neurologic deficits had previously been considered static, they were subjected to radiographic examination of the caudal spine and found to have a tethered cord. These 10 children were among 55 children with a tethered cord surgically treated at the Division of Neurosurgery of the Osaka Medical Center and Research Institute for Maternal and Child Health during the last 11 years. Data were obtained for these 10 children (6 boys and 4 girls, mean age 1.7 years) who underwent surgical untethering. Several hypotheses are offered to explain this association. Anorectal malformations are related to underlying spinal cord anomalies, which may be amenable to neurosurgical correction. Eight of our patients had no skin stigma of the lumbosacral region, in contrast to an ordinary tethered cord. Spinal cord imaging is necessary to closely scrutinize these children.

Abnormalities, Multiple↗

Multiplication of infantile spinal lipomas after surgical untethering. Report of two cases.

The authors reviewed 63 cases of patients with spinal lipomas who had undergone surgical untethering in childhood and found two infants in whom multiplication of the lipomas occurred within 1 year postoperatively. More importantly, the lipomas dramatically increased in size during infancy. In each case, the pathological findings on reoperation were identical to those in the first surgery. Subsequent imaging revealed no change in size of the lesions by 10 and 7 years after reoperation, respectively. This potential for growth of the lipomas should be kept in mind in infants with spinal lipomas who should undergo follow-up neuroimaging.

Female↗

Neurodevelopmental outcome in children with fetal hydrocephalus.

Thirty-eight children with fetal hydrocephalus treated surgically during the neonatal period were analyzed concerning their neurodevelopmental outcome by means of a follow-up study. The mean gestation at diagnosis was 31.1 weeks, and the mean postconceptual age at the first operation was 36.3 weeks. The ages of the patients at the last follow-up ranged from 3.8 to 11.8 years (mean = 7.4 years of age). During the follow-up period, they underwent neurologic examinations and were also evaluated to determine the developmental quotient or intelligence quotient. The relationships between age at diagnosis or the first operation for hydrocephalus and neurodevelopmental outcome, and between the lateral ventricular width/hemispheral width ratio at diagnosis and age at diagnosis or the first operation, and neurodevelopmental outcome were statistically evaluated. The neurodevelopmental outcome in the patients was normal in three patients, borderline intelligence in one patient, mental retardation in seven patients, and motor disturbance in 27 patients (five of whom were intellectually normal). The etiology was a major determinant of the outcome in the children with early postnatal surgical treatment of fetal hydrocephalus. Furthermore, an early onset and a high lateral ventricular width/hemispheral width ratio at diagnosis of hydrocephalus were significantly correlated with a poor intellectual outcome.

Cerebral Palsy↗

Spinal lipomas in children--surgical management and long-term follow-up.

Since its introduction, MR imaging has been easy to perform on all children with lumbosacral cutaneous stigmata, and has enabled the phenomenal refinement of spinal pathology. We investigated the overall outcomes of children with spinal lipomas at the Osaka Medical Center and Research Institute for Maternal and Child Health in Osaka, Japan. Between 1991 and 2003, 76 children with a tethered cord underwent a total of 90 surgical procedures at our institutes. Of this cohort, 67 cases had spinal lipomas. The mean age of patients at first operation for asymptomatic lipoma was 22.4 months (range: 1 month to 16 years, trim mean: 10.1 months, mode: 5 months), except 4 cases. The mean total follow-up for the cohort since the first surgical procedure was 7.2 years (trim mean: 7.9 years). Since the introduction of MR imaging, the reoperation rate for symptoms or signs in our series was 16.4% (11 cases). Regarding the 13 subsequent reoperations (2 patients had 2 operations), 3 patients were reoperated on due to multiplication of the lipomas after untethering, 3 due to urologic symptoms and 5 due to orthopedic signs. There were 2 cases who also had to undergo reoperation early due to CSF leakage. Filum and conus lipomas have similar tethering pathologies, but differ in the outcome following surgery. Filum lipomas are benign, and therefore surgery is safe and effective. Conus lipomas are more difficult to manage.

Adolescent↗