[Radical reconstructive surgery for apert dysraphic state preserving neuro-function and structure: operative technique for spina bifida aperta].
Explore the source record for details and available documents.
Humans↗
Biomedical subjects
S Oi
Publications and source records attributed to S Oi.
Synthesis of 5-fluorouridine 5'-diphosphate galactose from 5-fluorouridine by chemical phosphorylation and microbial uridylyl transfer.
Explore the source record for details and available documents.
Candida↗
The efficacy of shunting the hydrocephalic edema.
The efficacy of shunting the hydrocephalic edema was evaluated by means of transmission electromicroscopical observation (TEM) comparing ultrastructural alterations seen in either valid or invalid shunted feline hydrocephalus. Owning to shunt placement, deteriorated clinical symptoms recovered and one of the observed morphological alterations such as gliosis developed chronologically after the initiation of hydrocephalus. On the other hand, so called hydrocephalic edema observed in the region of periependymal tissue after shunt placement was improved not only in both valid and invalid shunted but also even in sham group however the extent of these alterations were different from each other. Among such observation, a distinct chronological linkage between the morphological alterations and clinical outcome was not noted. Our conclusions in present study were 1) shunt implantation results in the promotion of gliosis in the region of periventricular tissue in spite of the expected efficacy of shunt, 2) recovery of hydrocephalic edema was influenced not only by effective shunt implantation but also by the processes in chronological tissue reconstructions occurred in the natural course of hydrocephalus, and 3) early treatment of periventricular edema in hydrocephalus through shunting corrects the ill-fated neuro axis environments and reforming the intracranial conditions such as normalizing ICP and relieving hemodynamic distress seems to be more important than morphological recovery in treating hydrocephalus.
Animals↗
Aspartate aminotransferase from a thermophilic formate-utilizing methanogen, Methanobacterium thermoformicicum strain SF-4: relation to serine and phosphoserine aminotransferases, but not to the aspartate aminotransferase family.
The primary structure of the aspartate aminotransferase (AspAT) of an archaebacterium, Methanobacterium thermoformicicum strain SF-4, has been determined by cloning and sequencing of the gene for the enzyme. The gene had a consensus promoter and a ribosome binding sequence of methanogens in the 5' untranslated region, followed by an open reading frame starting with ATG and terminating with TGA. The deduced amino acid sequence was identical with the partial amino acid sequences of the enzyme including the N-terminal sequence, and the deduced molecular weight of 41,684 was virtually identical to that reported earlier for this enzyme [Tanaka, T., Yamamoto, S., Taniguchi, M., Hayashi, H., Kuramitsu, S., Kagamiyama, H., & Oi, S. (1992) J. Biochem. 112, 811-815]. The gene was expressed in Escherichia coli by inserting it into an expression vector just downstream of the lacZ promoter, and this verified that the cloned gene really encodes the Methanobacterium AspAT. The primary structure of the Methanobacterium AspAT showed extremely low homology, 5%, with AspATs of eubacteria, eukaryotes, and a thermoacidophilic arachaebacterium, Sulfolobus solfataricus. On the other hand, the Methanobacterium AspAT showed remarkable amino acid sequence homology, 31.5%, with rat serine:pyruvate aminotransferase and, 13.5%, with E. coli phosphoserine aminotransferase. Thus, the Methanobacterium AspAT apparently belongs to subgroup IV of the aminotransferases [Mehta, P.K., Hale, T.I., & Christen, P. (1993) Eur. J. Biochem. 214, 549-561], but not to subgroup I, in which all the AspATs known so far are included.
Amino Acid Sequence↗
Detection of norepinephrine distribution in rats with adrenal medulla autotransplants using 125I-meta-iodobenzyl guanidine.
The viability of autologous adrenal medullary transplants was evaluated using 125I-meta-iodobenzyl guanidine (MIBG), an adrenal medullary scanning agent. Bilateral cavities in the caudate nuclei were made stereotaxically in Wistar rats. One week later, the left adrenal medulla was resected by microsurgery, followed by reoperation of the cranium and implantation of a 0.5-1.0 mm diameter fragment of the adrenal medulla into the right caudate nucleus. Six weeks after the second operation, MIBG was administered intravenously. Specimens from both cerebral hemispheres, from the right adrenal medulla and blood were analysed by radioactivity counting. The radioactivity present in the blood of the transplanted group of 11.40 +/- 2.35 cpm mg-1 (mean +/- S.E.M.) was significantly higher than in the control group of 4.97 +/- 1.16 cpm mg-1 (P < 0.05). Radioactivity present in the right hemisphere of the transplanted group was 0.66 +/- 0.03 cpm mg-1, also significantly higher than in the control group which was 0.47 +/- 0.04 cpm mg-1 (P < 0.01). Autoradiography revealed increased radioactivity in the area of the transplants, which was also confirmed histologically.
3-Iodobenzylguanidine↗
Ventricular volume reduction technique--a new surgical concept for the intracranial transposition of encephalocele.
The authors propose a new operative technique for the intracranial transposition of an encephalocele by using the associated hydrocephalic state. In the first stage, the intracranial pressure buffering effect of the encephalocele sac is reduced by the closing of the dural defect. The repaired dural defect allows intraventricular pulse pressure to produce ventriculomegaly. In the second stage or in infants with hydrocephalus, the extracranially herniated brain is transposed into the intracranial cavity during ventricular shunting with appropriate drainage of cerebrospinal fluid.
Arnold-Chiari Malformation↗
[A new classification for congenital hydrocephalus [perspective classification of congenital hydrocephalus (PCCH)] and postnatal prognosis (Part 3). Neuronal maturation process and prognosis in neonatal hydrocephalus].
Seventy cases of neonatal hydrocephalus were analyzed regarding the prognosis using the newly developed concept, namely "Perspective Classification of Congenital Hydrocephalus [PCCH]". The results revealed that the prognosis of premature-neonatal hydrocephalus is not necessarily poor even in the early periods of the neuronal maturation (PCCH Stage- II/III). It was suggested that the major underlying pathophysiological difference between the premature-neonatal and fetal hydrocephalus in the same stage of neuronal maturation is the intracranial pressure dynamics. It was concluded that the fetal hydrocephalus should be treated in the early period of neuronal maturation as the form of neonatal hydrocephalus to avoid the insult of such high intracranial pressure dynamics in utero.
Fetal Diseases↗
Congenital frontal bone defect with intact overlying scalp.
An unusual case of a congenital frontal bone defect with intact overlying scalp and intact underlying dura mater is reported. Although spontaneous healing by the intact underlying dura mater by regeneration was expected, it did not occur. Cranioplasty was done for protective and cosmetic purposes. A review of the literature of congenital skull defects shows that spontaneous regeneration does not occur in this rare anomaly.
Child, Preschool↗
Potassium-stimulating mechanism of geranylgeranyl diphosphate synthase of Methanobacterium thermoformicicum SF-4.
The catalytic properties of geranylgeranyl diphosphate (GGPP) synthase [EC 2.5.1.29] purified from Methanobacterium thermoformicicum SF-4 were studied by kinetic procedures. The plots of 1/v versus 1/[S] and inhibition patterns by enzyme reaction products, PPi and GGPP, showed that the GGPP synthase reaction mechanism is an ordered-sequential Bi Bi one. Monovalent cations at low concentration (0.05 M) enhanced the enzyme activity, but at high concentration (0.4 M) they were inhibitory, except for K+. The K+ ion was found to be a modifier forming a parallel reaction pathway and accelerated the binding of substrates to the enzyme, especially the binding of isopentenyl diphosphate (IPP). When substrate concentrations are near the Km values, the rate-limiting step of the GGPP synthase reaction may be the substrate-binding step, probably the IPP-binding step, rather than the conversion step of the enzyme-farnesyl diphosphate-IPP complex to the enzyme-PPi-GGPP complex.
Alkyl and Aryl Transferases↗
Growth hormone-producing pituitary adenomas: MR characteristics and pre- and postoperative evaluation.
Twelve patients with growth hormone-producing pituitary adenomas were investigated to evaluate correlations between magnetic resonance (MR) appearance and tissue characteristics, sellar expansion, suprasellar tumor extension, and tumor consistency. MR imaging could detect microadenomas with a characteristic enhancement delay of gadolinium-diethylenetriaminepenta-acetic acid in the surrounding normal pituitary gland. Macroadenomas and giant tumors appeared on T2-weighted images as mostly high intensity, while varied greatly on T1-weighted images. The signal intensities of growth hormone-producing adenomas were more homogeneous (80%) than those of other functioning and non-functioning adenomas on T1-weighted images. However, there was no typical MR imaging for the tissue characteristics of the growth hormone-producing adenomas, and no particular correlation with suprasellar extension or consistency. Postoperative MR findings showed that the transcranial approach was superior for total or subtotal removal of large tumors, especially with suprasellar extension up to the upper third ventricle. The transsphenoidal approach can achieve a satisfactory decompressive effect on the optic chiasm, but more radical removal is required to achieve a normal hormone level.
Acromegaly↗
Myelomeningocele and thick filum terminale with tethered cord appearing as a human tail. Case report.
Tail-like caudal appendages may be associated with spinal dysraphism, particularly with spinal lipomas or lipomyelomeningoceles. An unusual case is presented of a patient with a myelomeningocele and a thick filum terminale with tethered spinal cord, which presented with the external appearance of a human tail. A review of the literature reveals that human tails may be associated with dysraphic conditions. Extensive neuroradiological examinations should be performed for all such cases of apparent tails.
Abnormalities, Multiple↗
UK-1, a novel cytotoxic metabolite from Streptomyces sp. 517-02. I. Taxonomy, fermentation, isolation, physico-chemical and biological properties.
A new benzoxazole, UK-1, was isolated from the mycelial cake of an actinomycete strain 517-02. Based on morphological, cultural and physiological characteristics, strain 517-02 was seemed to be a close relative of Streptomyces morookaense. UK-1 showed potent cytotoxic activity against B16, HeLa and P388 cells and did not show any antimicrobial activity.
Animals↗
Controversy pertaining to therapeutic modalities for tumors of the pineal region: a worldwide survey of different patient populations.
The management of tumors of the pineal region differs between Western countries and Japan. This paper reports on a worldwide survey of individual experience and regimens for treating pineal region tumors in different patient populations. Fifteen pediatric neurosurgeons from nine different countries participated in the survey, and a total of 408 pineal region tumors were evaluated. Determination of tumor histology as an initial procedure was strongly supported by the majority of neurosurgeons in North and Central America and Europe (group A), whereas all but one from Asia and Egypt (group B) emphasized initial application of the radiation test. The analysis of patient populations clearly revealed racial differences in tumor type which explain this discrepancy. Germinoma, the most radiosensitive tumor, constituted 43-70% (mean: 53.7%) of tumors in group B, followed by teratoma, pineoblastoma, and others, whereas in group A the incidence of germinoma was only 21-44% (mean: 34.7%), followed by a variety of tumors, such as astrocytoma, pineoblastoma, etc. The age distribution among intracranial germ cell tumors (GCT) obtained from data from the Brain Tumor Registry in Japan also demonstrated clear differences in the incidence of tumor types in different age groups in Japan: while germinoma constituted 70-84% of GCT in patients between the ages of 15 and 35 years, the incidence was much lower before 15 years and after 35 years, being 24% of tumors under 4 years and 34% of tumors after 40 years of age. The therapeutic regimen for pineal region tumors should depend on the patient population concerned, because of the differences relating to race and age distribution.
Adolescent↗
A proposed grading and scoring system for spina bifida: Spina Bifida Neurological Scale (SBNS)
Neurological symptoms present in neonates with spinal dysraphism often progress with growth. A simple, objective scoring system for quantitative analysis of spinal neurological deficits, called the Spina Bifida Neurological Scale (SBNS), is proposed. Scoring is based on (1) motor function, (2) reflexes, and (3) bladder and bowel function. These are each divided into six, four, and five points respectively with respect to the level of spinal function. Motor function and reflexes are bilaterally analyzed, and the maximum SBNS score of 15 points reflects a normal spinal neurological state (grade I). This scoring system was correlated with the clinical condition of 89 patients with spina bifida who were graded from I to V. A total score of less than 5 was associated with a nonambulatory state (grade IV or V) in 84.0% of patients, and a score of 5-9 was associated with an ambulatory state (grade III) in 93.8% of patients. Scores of 10-14 reflected control of bladder and bowel function (grade II) in all patients. The application of a standardized scoring scheme will assist in the evaluation of patients' clinical status and will enable analysis of chronological changes in neurological function.
Adolescent↗
Histological changes in the midbrain around the aqueduct in congenital hydrocephalic rat LEW/Jms.
Primary aqueductal stenosis is one of the main causes of congenital hydrocephalus in humans and experimental models. The congenitally hydrocephalic rat strain LEW/Jms is one such model. In this report, we describe further detailed histological features of periaqueductal structure, including the posterior commissure, subcommissural organ (SCO), and ependyma, and discuss the changes in these structures in relation to the cause of hydrocephalus. Coronal sections of the aqueduct in normal rats showed that the usual ependyma was absent in the center of the base facing the dorsal side, which was replaced by tall columnar cells. On the other hand, in hydrocephalic rats the ependyma encircled the aqueductal cavity. In midline sagittal sections, normal and hydrocephalic rats showed the SCO, although the SCO in hydrocephalic rats was shorter than in normal rats. There was also a marked difference between normal and hydrocephalic rats in the dorsoventral dimension of the rostral midbrain. In hydrocephalus, this dimension was large in comparison with normal rats. The superior collicular commissure located caudal to the posterior commissure ran along the ventral side of the midbrain in rats with hydrocephalus, and there was a cell-depleted area just dorsal to the superior collicular commissure. The same findings were observed from the 17th day of gestation until the postnatal period. Although the role of the SCO has been widely discussed from the viewpoint of secretory function, the present study indicated that this organ might be involved in the formation of the shape of the aqueduct.
Animals↗
Is the hydrocephalic state progressive to become irreversible during fetal life?
Explore the source record for details and available documents.
Fetal Diseases↗
Further studies on aspartate aminotransferase of thermophilic methanogens by analysis of general properties, bound cofactors, and subunit structures.
Aspartate aminotransferase (AspAT) [EC 2.6.1.1] of thermophilic methanogen was further characterized with the enzyme from Methanobacterium thermoautotrophicum strain FTF-INRA as well as M. thermoformicicum strain SF-4. AspAT of strain FTF-INRA was similar in the amino donor specificity to the enzyme of M. thermoformicicum strain SF-4, in that it was active on L-cysteine and L-cysteine sulfinate in addition to L-glutamate and L-aspartate. The enzymes gave similar absorption spectra having maxima at around 326 and 415 nm with no pH-dependent shift but were found to contain 1 mol of tightly bound pyridoxal 5'-phosphate (PLP) per subunit. Reconstitution of each apoenzyme with added PLP resulted in partial recovery of the original enzymatic activity, suggesting a significant conformational change of the active site region upon removal of the cofactor. Polyacrylamide gel electrophoresis (PAGE) and gel filtration analyses revealed a tetrameric structure (180 kDa) of identical subunits with a molecular mass of 43 kDa for each of these enzymes. Electric current was found to affect the interaction or affinity of each subunit, promoting dissociation of the native enzyme into the monomeric form. Alkaline treatment was effective only for dissociation of the enzyme from strain SF-4. They were distinguishable by the more rapid reassociation of the monomer to the native aggregated form in the enzyme of strain FTF-INRA.
Aspartate Aminotransferases↗
[Radical reconstructive surgery for apert dysraphic state preserving neuro-function and structure: operative technique for cranium bifidum apertum].
Explore the source record for details and available documents.
Brain↗