Biomedical subjects

O Takemoto

Publications and source records attributed to O Takemoto.

At least 19 recordsLinked to original sources

PubMed2000

[Neonatal hydrocephalus-volume determinations using computed tomography].

Computed tomography potentially offers the most accurate noninvasive means of estimating in vivo volumes. Contiguous 5 and 10-mm-thick CT scans were obtained through phantom and neonatal cranium. Cross-sectional areas were calculated for each individual scan and volumes then determined with summation-of-areas technique. The indirect intracranial volume measurement technique was then used to compare hydrocephalic and non-hydrocephalic intracranial and ventricular volumes in nine neonates. Our findings show that intracranial volumes of hydrocephalic neonates with head circumference of more than 39 cm, have 1.97 times larger than control group. The ratios of lateral ventricle versus intracranial volume are 0.57 +/- 0.2 in hydrocephalic babies and 0.0062 +/- 0.001 in control babies, respectively(p < 0.005).

Brain↗

PubMed1999

BDNF atelocollagen mini-pellet accelerates facial nerve regeneration.

We investigated the effect of BDNF mini-pellet on the GAP-43 mRNA expression and functional status of facial nerve in a rat model of facial nerve transection and immediate repair. The facial function started to recover at 17 days in the placebo group and 14 days in the BDNF group. BDNF group had shorter period of increased GAP-43 mRNA expression than the placebo group. Topically applied BDNF may accelerate the facial nerve regeneration.

Animals↗

PubMed1999

Immunoelectron microscopic study of c-Fos, c-Jun and heat shock protein after transient cerebral ischemia in gerbils.

The neuroprotective role of the expression of heat shock protein (HSP) and immediate early gene remains unclear. Using immunoelectron microscopy, we examined the ultrastructural integrity of the neurons with expression of c-Fos, c-Jun and HSP70 in gerbils after transient cerebral ischemia and reperfusion. Induction of c-Fos and c-Jun was observed in the CA3 region resistant to ischemia, while HSP70 was expressed not only in the CA3 but also in the vulnerable CAI region. With immunoelectron microscopy, the expression of c-Fos/c-Jun and HSP70 was observed in the neurons which retained neuronal integrity except for mitochondrial swelling and polyribosomal disaggregation. In contrast, the CAI neurons without immunoreaction for HSP70 showed cytoplasmic vacuoles and parallel stacking of rough endoplasmic reticulum, the features associated with the process of delayed neuronal death. These findings suggested that c-Fos and c-Jun were induced selectively in reversibly damaged neurons, whereas HSP70 was up-regulated even in neurons with irreversible damage, but was more preferentially and intensely expressed in neurons with reversible damage.

Animals↗

PubMed1999

[Follow-up of children with early neonatal surgery of fetal hydrocephalus].

This is a retrospective study of patients with surgically treated antenatal diagnosed hydrocephalus. We conducted the study to elucidate the outcomes of the patients, as well as potential pitfalls in their care. A series of 51 patients underwent surgical intervention between 1987 and 1997. All lesions were diagnosed by antenatal ultrasound sonography. After the estimation of their lung maturation, they were delivered in early pregnancy stage and the operation had performed for hydrocephalus. 43 children could be followed-up. To estimate the morphological improvement from radiological examinations objectively, we compared cerebroventricular index (CVI) of pre-operation with that of post-operation. The result was that excellent improvement group was 18 cases, good improvement group was 13 cases, fair improvement group was 8 cases and poor improvement group was 4 cases. In 43 cases, 20 children also had myelomeningocele and in them the improvement of hydrocephalus was that excellent improvement group was 10 cases, good improvement group was 5 cases and fair improvement group was 5 cases. About motor function of 20 children with myelomeningocele, only 5 children were ambulatory with brace. Attending to the rest 23 children without myelomeningocele, 6 children in 8 excellent improvement cases and 6 children in 8 good improvement cases were ambulatory by themselves. But all 7 children belonging to fair and poor improvement groups were unambulatory. We concluded that it was necessary to improve dilated ventricle on the radiological examinations with surgical procedure in order to get better motor function, even semilobar and lobar holoprosencephaly.

Child Development↗

PubMed1999

[Urodynamic studies on the untethering of spinal lipoma in the children].

We performed conus untethering on 44 children with spinal lipoma. In this retrospective study, we studied urological examinations obtained in 36 consecutive patients. Urological examinations were ultrasonography of bladder and kidney, voiding cystourethrography (VCG), and urodynamic cystometry. In those of them, 6 patients had already had urinary dysfunction at preoperative stage, but 4 patients' spinal lipoma was one complication of cloaca exstrophy and 2 patients' spinal lipoma after repairment of their myelomeningocele. In the remaining 30 cases, 18 patients (60.0%) as the group 1 did not have urinary dysfunction and abnormality in any urological examinations. Another 7 patients (23.3%) as group 2 also did not have urinary dysfunction, but abnormal vesicoureteral reflux (VUR) was found out in their VCG examination. At postoperative stage, abnormal VUR resolved or improved in all these 7 cases, but one of them showed transient urinary retention. Two patients of 18 in the group 1 had to require clean intermittent self-catheterization at postoperative stage. These observations confirmed that children with spinal lipoma were more likely to present with urological findings, and so it was imperative that a diagnosis be made and treatment be instituted as early as possible.

Child, Preschool↗

PubMed1999

[Vein of Galen aneurysmal malformation: multi-staged feeder clipping in two neonatal cases with intractable heart failure].

The authors reported the surgical experience of two cases of vein of Galen aneurysmal malformation in the newborn, whose congestive high-output cardiac failure was intractable. Along with the intensive care to clinical manifestations of the heart failure, multi-staged feeder clipping was carried out to decrease the high-flow shunt of the malformation. As stages going on, heart failure was relieved gradually and cathecolamines were weaned. Although certain retardation became apparent in both cases, they are showing satisfactory development in the long-term follow up. By the recent advancement of the embolization technique, the embolization appears to have already taken place the treatment of choice for this malformation. According to the neonatal evaluation score of Lasjaunias, the embolization would no longer be recommendation in neonates, whose general condition scored less than eight points. The authors believe, based on our two cases, that multi-staged feeder clipping is one of the effective modality of treatment in neonates of the vein of Galen aneurysmal malformation with severe multiorgan failure.

Cardiac Output, High↗

PubMed1999

[Germinal matrix hemorrhage and hydrocephalus in premature infants].

An analysis of 25 preterm infants with grade 3 or 4 intraventricular hemorrhage and surgically treated progressive hydrocephalus was undertaken to assess mortality, cognitive outcome and motor deficit. All patients underwent surgery at the author's institute since 1981 and represented 4.7% of all intraventricular hemorrhage in premature infants. Surgical procedure was initial placement of a miniature Ommaya's reservoir and conversion to a ventriculoperitoneal shunt diversion. Overall, outcomes were achieved in 64.7% of ambulatory and improvement of cerebroventricular index on follow-up CT image from 0.68 +/- 0.36% to 0.36 +/- 0.31%. The presence of intraventricular hemorrhage continues to be a major problem in low birth weight infants whose rate survival continues to increase as the major improvements in perinatal medicine. We feel that miniature Ommaya's reservoir is quite helpful in the treatment of posthemorrhagic hydrocephalus in the preterm infant who prove refractory to aggressive conservative therapy.

Cerebral Hemorrhage↗

PubMed1999

[Computed assisted area measurement using CT scans: clinical application for craniosynostosis in children].

This paper describes a method for obtaining intracranial area measurements using CT scans with a software for quantitative analysis of tracing data. A Toshiba CT 1010 scanner was used (120 kv, 10 mm slice thickness) to examine 13 children before and after cranioplastic surgery for craniosynostosis. Using Scion Image (Scion Corporation) with Intuos tablet system (WACOM), the intracranial space was measured at approximately same scanning level. Our findings show that the reverse pi and bilateral canthal advancement procedures usually carried out are associated with increased intracranial area, 4.5 +/- 2.1% and 12.0 +/- 8.3%, respectively. This measurement method should be further modified to intracranial volume gain by several surgical procedures.

Craniosynostoses↗

PubMed1999

[Spinal lipoma in children: analysis of magnetic resonance image for upward displacement of medullary-conus on 44 consecutive surgical cases].

Medullary conus-untethering operation was conducted on 52 infants with spinal lipoma. Magnetic resonance (MR) image was used in order to evaluate the untethering results in 44 out of these 52 patients who could be followed-up after Osaka Medical Center & Research Institute for Maternal & Child Health was opened. Talking into account the changes in vertebral body during the growth period of infants, the authors studied the upward displacement of the conus-lipoma interface by four fractional MR sagittal image, using the vertebral body-intervertebral disc space as the baseline. Upward displacement was confirmed in 27 of 44 (61.4%). The mean, median and trimmed mean of upward displacement were 1.78 +/- 0.80, 2.0, 1.70 fractions, respectively. Sixteen (59.3%) were caudal type, 10 (37.0%) were transitional type and 1 (3.7%) was dorsal type. By type of spinal lipoma, upward displacement was observed in 16 of 23 caudal type patients (69.6%), 10 of 16 transitional type patients (62.5%) and 1 of 5 dorsal type patients (20%). While the rate of upward displacement was almost equal between the caudal and transitional type, that of dorsal type was lower. However, statistical analysis for the difference in population percentage of the three groups showed that significant difference existed only in the caudal type group.

Female↗

PubMed1998

Distribution of nerve growth factor in cat brains following topical application of solution or Minipellet.

The distribution of nerve growth factor (NGF) was studied after topical application of NGF solution or NGF Minipellet into the caudate nucleus of cat brains. Each aliquot of NGF solution or a piece of NGF Minipellet contains 200 micrograms of mouse 2.5S beta-NGF. The concentrations of NGF in various areas of the brain were determined by enzyme-linked immunosolvent assay (ELISA). The tissue concentrations of NGF were very high at 6 h after injection of NGF solution (124.0 +/- 2.46 to 2144.0 +/- 16.03 ng g-1), but quickly decreased on day 1. The tissue concentrations of NGF were low at 6 h after implantation of NGF Minipellet, but were considerably increased on day 1 (11.22 +/- 3.36 to 72.04 +/- 20.45 ng g-1), and slowly decreased during the following 6 to 14 days. The present study demonstrates the temporal and spatial profiles of NGF distribution in the brain of middle-sized animals after topical application. Injection of NGF solution resulted in abrupt, but very transient, elevation of tissue NGF. Implantation of NGF Minipellet maintained the tissue NGF at biologically effective levels for 6 to 14 days.

Administration, Topical↗

PubMed1998

[Anesthesia and perioperative management in infants with Chiari type II malformation].

From July 1991 to June 1997. 15 neonates with Chiari type II malformation were treated at our institution. Four of them required posterior fossa decompression and cervical laminectomy for hindbrain decompression. We report anesthesia and postoperative management in these four patients. They had a fetal diagnosis of hydrocephalus and was delivered by caesarean section. They underwent Ommaya reservoir placement for drainage and repair of myelomeningocele in the neonatal period. They developed respiratory depression as apneic spells or retraction with or without swallowing difficulties and underwent posterior fossa decompression and cervical laminectomy at 20-87 days of life. One patient died of asthma at the age of 2 years and 8 days and others are doing well. Patients with this malformation may develop respiratory depression such as apneic spells and vocal cord paralysis even if the intracranial pressure is well controlled and they should be monitored carefully for the signs of apnea and the compromised airway.

Anesthesia, General↗

PubMed1998

[Manifestation of Chiari II symptoms following peritoneal shunt tube extension].

A 5-year-old boy with hydrocephalus and a lumbar myelomeningocele underwent extension of peritoneal tube of ventriculoperitoneal (VP) shunt system. Prior to the operation he had been able to walk independently with the use of braces, to speak complex sentences and to sing songs. After the surgery, he lost consciousness and became critically ill with irregular respiration. He was artificially ventilated for 10 days, and then recovered, with sequelae of right facial paresis and slight dysarthria. T1 weighted magnetic resonance image showed high intensities of the medial part of the inferior lobe of the cerebellum and medulla oblongata, which were interpreted as representing edema. This case illustrates that Chiari II malformation can become symptomatic after a VP shunt trouble.

Acute Disease↗

PubMed1998

[A case of congenital toxoplasmosis confirmed by detection of Toxoplasma gondii in placenta].

We report a case of congenital toxoplasmosis with a prenatal diagnosis of fetal hydrocephalus. A CT scan performed at birth revealed ventricular dilation with calcification. The serum and CSF Toxoplasma specific IgM were elevated. The diagnosis was confirmed by the presence of Toxoplasma cysts in the placenta, and detection of the Toxoplasma SAG1 gene by a polymerase chain reaction (PCR) (placenta, positive; CSF, negative). Signs of active central nervous system infection, such as the decreased CSF glucose, and elevated CSF protein, neuron specific enolase and LDH, resolved after initiation of treatment with pyrimethamine and sulfazoxine. A PCR test using the placental tissue may be useful for the rapid diagnosis of congenital toxoplasmosis.

Adult↗

PubMed1998

[Hydromyelia associated with spinal lipoma].

We studied morphological changes of hydromyelia complicated with spinal lipoma of infants who were untethered. Since the MRI was introduced, early detection of spinal lipoma with lumbosacral skin abnormalities has become possible. We have experienced 44 surgical cases of spinal lipoma. Out of 36 such cases, 25 (69.4%) had hydromyelia, and hydromyelia of 9 patients was found to be of the terminal ventricle type. As many as 36% of spinal lipoma patients with hydromyelia concurrently had terminal-type hydromyelia, which was considered to fall under a specific category of congenital hydromyelia. At the stage of embryogenesis of the spinal cord, the caudal cell mass undergoes vacuolization, canalization and retrogressive differentiation, and during this process, the terminal ventricle with ependymallined cells becomes morbid. Though the morphological changes of hydromyelia after surgery as untethering were varied, hydromyelia of 9 patients became smaller after untethering, and hydromyelia of 8 expanded but attenuated afterwards, totaling 17 (68.0%). However, 5 had an expanding tendency and 3 did not show any morphological changes during the follow-up period (20.6-26.9 months) by MRI.

Child↗

PubMed1997

Topical application of fibrin adhesive in the rat brain: effects on different cellular elements of the wound.

Although fibrin adhesives are popular in the field of neurosurgery, the medical literature is devoid of study elucidating their effects on the brain tissue. To study the safety of applying fibrin glue to the brain and to explore new surgical potentialities, we implanted soft pellets made of fibrin glue into the brains of Wistar rat. Following 6 h and 3, 7 and 14 days post-implantation survival, the brains were removed and paraffin sections were processed for hematoxylin-eosin staining, as well as immunohistochemistry for microtubule-associated protein (MAP-1A) and glial fibrillary acidic protein. The changes in the neuronal and glial elements and also the numbers of inflammatory and endothelial cells in the vicinity of implanted fibrin glue pellets were compared with those of gelfilm pellets. The results demonstrated that topical application of fibrin glue to the brain causes significantly enhanced local accumulation of mononuclear cells and promoted angiogenesis close to the wound while not affecting the neuronal and glial elements. These findings suggest that fibrin glue can be considered as a safe supportive material for intradural procedures directly involving the brain tissue.

Adhesives↗

PubMed1997

Chromosome 22q allelic losses at microsatellite loci in human astrocytic tumors.

Common regions of deletion(s) on chromosome 22q and the correlations between loss of heterozygosity and patient survival were analysed in 18 deoxyribonucleic acid samples from astrocytic tumors (3 astrocytomas, 5 anaplastic astrocytomas, and 11 glioblastomas) and matched normal brain tissues. The polymerase chain reaction products using five microsatellite markers were electrophoresed on polyacrylamide gels and the ethidium bromide stained bands were photographed. Loss of heterozygosity was observed in 14 (74%) of 19 samples, with similar incidences in astrocytomas, anaplastic astrocytomas, and glioblastomas (67%, 80%, and 82%, respectively). The locus D22S300 (q12.1-q13.1) was most frequently involved, with loss of heterozygosity in eight (80%) of 10 informative glioblastomas at this locus. Increased loss of heterozygosity during tumor progression or recurrence was seen in two patients at the D22S300 (q12.1-q13.1) and TOP1P2 (q11.2-q13.1) loci. No correlation between loss of heterozygosity on chromosome 22 and the postoperative survival was found. These findings suggest that loss of heterozygosity on chromosome 22q probably occurs quite frequently in astrocytic tumors. The chromosome segment 22q12.1-q13.1, around the D22S300 locus, may be the common region of deletion in glioblastomas.

Adult↗

PubMed1995

Superficial temporal artery to superior cerebellar artery anastomosis via the presigmoid retrolabyrinthine transtentorial approach.

BACKGROUND: The conventional method for performing superficial temporal artery to superior cerebellar artery (STA-SCA) anastomosis is applied to ischemic lesions in the posterior circulation via the temporobasal approach. However, this approach can be difficult and presents limitations due to the deep and narrow surgical field. METHODS AND RESULTS: STA-SCA anastomosis using the presigmoid retrolabyrinthine transtentorial approach was performed, in which a large skin incision was required for the isolation of the STA, compared to that associated with the petrosal approach as described in previous reports. The superior petrosal sinus was sacrificed, and the tentorium cerebelli was cut up to the level of the incisula. Being very close to the surface opening, the SCA was approached easily at the ambient portion without any danger to the vein of Labbe. The SCA ran perpendicularly upward in the surgical field, which was advantageous in performing the anastomosis. CONCLUSION: The presigmoid retrolabyrinthine transtentorial approach may provide a better surgical strategy than the temporobasal approach in performing STA-SCA anastomosis.

Anastomosis, Surgical↗

PubMed1995

Induction of c-fos and c-jun gene products and heat shock protein after brief and prolonged cerebral ischemia in gerbils.

BACKGROUND AND PURPOSE: Proto-oncogene activation and induction of heat shock protein (HSP) occur in response to various stimuli to brain, but the role in neuronal survival after cerebral ischemia remains uncertain. We compared the extent of insults and induction of c-fos and c-jun gene products (c-FOS and c-JUN) as well as HSP in ischemic and postischemic gerbil brains immunohistochemically. METHODS: Common carotid arteries of Mongolian gerbils were occluded for 5 or 15 minutes and recirculated for 0 minutes to 7 days. Antibodies for c-FOS, c-JUN, and HSP 70 were used for immunohistochemistry, and positive reactions were semiquantitatively analyzed. The presence of ischemic and postischemic lesions was ascertained with an antibody for microtubule-associated proteins. RESULTS: After ischemia for 15 minutes and reperfusion, c-FOS was induced promptly after 1 to 6 hours in pyramidal cells of the CA3 and CA4 regions, while c-JUN became visible in the same areas after recirculation for 4 to 48 hours. HSP 70 was detected after recirculation for 24 hours in the CA3 region. In layers I and II of the cerebral cortex, c-FOS and c-JUN peaked at 3 hours and HSP 70 at 96 hours. Induction of these proteins was absent or negligible in the areas that developed ischemic or postischemic lesions, including the subiculum-CA1 and CA1 regions of the hippocampus and layers III/IV and Vb/VI of the cerebral cortex. After shorter ischemia for 5 minutes and reperfusion, c-FOS and c-JUN were rapidly induced at 15 minutes to 1 hour except for the subiculum-CA1 and CA1 regions of the hippocampus. Induction of HSP 70 did not occur for 24 hours and was noted only in the hippocampus. CONCLUSIONS: Induction of c-FOS and c-JUN occurred in the areas surviving after transient cerebral ischemia, but the extent of induction and the latent period varied depending on the duration of the insult and the location. In the areas with ischemic or postischemic damage detected by loss of the reaction for microtubule-associated proteins, the induction of c-FOS and c-JUN was either absent or minimal, suggesting that active induction of those immediate early gene products occurred early in surviving neurons. On the other hand, the induction of HSP 70 did not occur until reperfusion for 24 hours and actively occurred only in the areas with earlier induction of c-FOS and/or c-JUN, suggesting that the induction of HSP 70 occurred in neurons that survived to that point, but it did not participate in early responses for neuronal survival after global cerebral ischemia.

Animals↗