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Biomedical subjects

G Takada

Publications and source records attributed to G Takada.

At least 37 records · Page 2Linked to original sources
PubMed2001

[A case of carbamazepine intoxication with alpha coma and status epilepticus].

We report a 14-year-old girl with carbamazepine intoxication who developed alpha coma and status epilepticus. She fell into deep coma and developed frequent generalized convulsions. The EEG during coma showed diffuse alpha activity predominantly in the frontal area. Serum carbamazepine concentration was 42.8 micrograms/ml. The convulsions were suppressed by diazepam only transiently, and by midazolam completely. Although half a day had passed since carbamazepine ingestion, we could wash out much of drug remnants by gastric lavage. Thereafter, the serum concentration of carbamazepine decreased efficiently and the patient recovered dramatically without complication. Early diagnosis and appropriate treatments should improve the prognosis of carbamazepine intoxication.

Adolescent↗
PubMed2000

SLC7A7 genomic structure and novel variants in three Japanese lysinuric protein intolerance families.

Lysinuric protein intolerance (LPI) is a rare inherited disease caused by defective transport of the dibasic amino acids at the basolateral membranes of epithelial cells in the renal tubules and small intestine. The metabolic defect leads to brain dysfunction caused by hyperammonemia with a functional impairment of the urea cycle. Recently, mutations in the human SLC7A7 cDNA coding for y(+)LAT-1, which express dibasic amino acid transport activity, were reported to be responsible for LPI. In the present study, we examined the genomic structure of SLC7A7 by DNA sequencing of PCR products, and determined that the gene had 11 exons and 10 introns spanning about 18 kb of genomic DNA. We also identified an alternative RNA splicing at the 5' untranslated region of the SLC7A7 mRNA in human peripheral blood leukocytes, cultured lymphoblasts, and fibroblasts. As a result of mutational analysis of SLC7A7 in three Japanese LPI families, we found a nonsense mutation (R410X), a splicing mutation(911+1G>A) in intron 4, and four silent polymorphisms (201C/T, 445A/G, 784C/T, 946T/C). Identification of the genomic structure of SLC7A7 may provide a molecular basis for a genetic survey for LPI.

5' Untranslated Regions↗
PubMed2000

A cluster of lysinuric protein intolerance (LPI) patients in a northern part of Iwate, Japan due to a founder effect. The Mass Screening Group.

Lysinuric protein intolerance is an autosomal recessive disease characterized by defective transport of the dibasic aminoacids. Mutational analysis of LPI patients in the northern part of Japan revealed that six were homozygous for the R410X mutation and two others were compound heterozygotes of R410X and other unknown mutations. In the population epidemiology study in a local cluster in the northern part of Iwate, ten heterozygotes were found in 1190 newborn babies leading to an estimated LPI incidence of 1/57,000. Polymorphism analysis revealed two major alleles, A and B, in intron 8. While the population frequency of allele A was 0.9 and that of allele B was 0.1 in the northern part of Japan the R410X mutations were exclusively on allele B in 31 chromosomes suggesting a founder effect. Genetic analysis in patients revealed strong linkage disequilibrium with D14S283 and TCRA indicating that the R410X mutation occurred before at least 130 generations ago (about 2600 years). The R410X mutation was shown to be useful as a molecular marker for screening LPI patients in the northern part of Japan.

Amino Acid Metabolism, Inborn Errors↗
PubMed2000

Progressive facial hemiatrophy after epileptic seizures.

Intractable complex partial seizures developed in a 3-year-old female with normal intracranial findings on computed tomography. Frontal paramedian band-like depression of the skin gradually developed thereafter, and progressive facial hemiatrophy (Parry-Romberg syndrome) was diagnosed. Computed tomography scanning at 5 years of age revealed multiple parenchymal calcifications and low-density areas in the white matter of the frontoparietal lobes. Epileptic seizures, one of the major neurologic complications of progressive facial hemiatrophy, could precede the succeeding neurocutaneous changes.

Child, Preschool↗
PubMed2000

Mass production of D-psicose from d-fructose by a continuous bioreactor system using immobilized D-tagatose 3-epimerase.

An improved process for the mass production of D-psicose from D-fructose was developed. A D-fructose solution (60%, pH 7.0) was passed at 45 degrees C through a column filled with immobilized D-tagatose 3-epimerase (D-TE) which was produced using recombinant Escherichia coli, and 25% of the substrate was converted to D-psicose. After epimerization, the substrate, D-fructose, was removed by treatment with baker's yeast. The supernatant was concentrated to a syrup by evaporation under vacuum and D-psicose was crystallized with ethanol. Approximately 20 kg of pure crystal D-psicose was obtained in 60 d.

Journal Article↗
PubMed2000

Restricted usage of T-cell receptor alpha-chain variable region (TCRAV) and T-cell receptor beta-chain variable region (TCRBV) repertoires after human allogeneic haematopoietic transplantation.

We analysed T-cell receptor alpha-chain variable region (TCRAV) and T-cell receptor beta-chain variable region (TCRBV) repertoires in peripheral blood mononuclear cells (PBMCs) from 34 recipients of allogeneic bone marrow transplantation (allo-BMT), seven of allogeneic peripheral blood stem cell transplantation and 19 of autologous peripheral blood stem cell transplantation using the quantitative microplate hybridization assay. TCR usage skewed at an early period (6-7 weeks) after BMT. The change was more apparent in allogeneic recipients than in autologous recipients. In particular, a predominant increase was detected in the frequency of VA1-4 (26%, 11 of 41 recipients), VA3-1 (32%) and VB24-1 (28%). Interestingly, acidic amino acid residues frequently followed the arginine residue in complementarity-determining region 3 of BV24S1. We further examined the extent of skew using samples obtained at serial time points after transplantation. The normalization of skewed repertoires occurred over a long period of time (> 8 years). There was a significant difference in the rate of normalization of skewed TCR repertoires between adult and child recipients (P < 0.05). The results suggest that these T cells may have expanded in response to allogeneic antigens, such as miHA (minor histocompatibility antigen), and that altered repertoires are eventually normalized by T-cell regeneration via a thymic-dependent pathway in children.

Adolescent↗
PubMed2000

Prolonged activation of the hypothalamus-pituitary-gonadal axis in a child with X-linked adrenal hypoplasia congenita.

X-linked adrenal hypoplasia congenita (AHC) is a rare developmental disorder of the human adrenal cortex that is caused by a mutation of the DAX-1 gene, a member of the nuclear hormone receptor superfamily. Hypogonadotrophic hypogonadism is frequently associated with this disease and the DAX-1 mutation is known to impair gonadotrophin production by acting at both the hypothalamic and pituitary levels. However, three recent studies reported that the hypothalamic-pituitary-gonadal axis was active in six infants with AHC, suggesting that a difference exists in the central regulation of hypothalamic-pituitary-gonadal activity between infant boys and pubertal boys. To determine the effect of the DAX-1 gene mutation on the axis in early childhood, we measured testosterone, LH, and FSH and performed LH-releasing hormone tests on a boy with AHC from birth to 3 years of age. Surprisingly, our findings showed that the axis was active from the infantile period to 3 years of age. This delayed initiation of the prepubertal pause, or prolonged activation of the axis, indicates that the DAX-1 gene is related to the control mechanism of the prepubertal restraint of gonadotrophin secretion.

Adrenal Insufficiency↗
PubMed2000

Development of a rapid blood transfusion system with the capability of blood purification.

Blood is usually irradiated by x-ray to prevent graft-versus-host-disease. However, plasma potassium levels of irradiated blood are rapidly increased during preservation in irradiated blood. The objectives of this study were to develop a rapid blood transfusion system for which irradiated blood can be used and to evaluate the capability of blood purification of the system. Packed red blood cells (RBC) were irradiated (15 Gy x-ray) at 21 days and preserved until 42 days after collection. A blood mixture of RBC and plasma was perfused through a dialyzer at 25, 50, 100, and 200 ml/min. Dialysate was perfused at 100, 100, 500, and 500 ml/min, respectively. Preperfusion levels of sodium, 121; potassium, 35; and chlorine, 76 mEq/L were changed to sodium, 144 to 146; potassium 2.5 to 3.0; and chlorine, 105 to 110 mEq/L, which were comparable with the levels in dialysate after perfusion for 25, 50, and 100 ml/min perfusion groups. For the 200 ml/min perfusion group, potassium was 5.3 mEq/L after perfusion which was slightly higher than other groups, but 84% of the potassium was removed by the system. Citrate levels were significantly decreased to 3.4, 28, 31, and 81 mg/dl for the 25, 50, 100, and 200 ml/min groups, respectively, after perfusions. The rapid transfusion system composed of the dialyzer and the blood pumps was effective in the removal of potassium and in the normalization of electrolytes. Irradiated blood with high levels of potassium can be safely and effectively used for this system in cases requiring massive rapid blood transfusion.

Blood Preservation↗
PubMed2000

Cloning and sequencing of an endoglucanase gene from Scopulariopsis brevicaulis TOF-1212, and its expression in Saccharomyces cerevisiae.

The egI gene, encoding a major endoglucanase (EGI) of Scopulariopsis brevicaulis TOF-1212, was cloned and sequenced. The eglgene consisted of 868 bp with one intron and encoded a protein of 229 amino acids with a calculated molecular mass of 22,392 daltons. The EGI was assigned to a family 45 of glycosyl hydrolases and showed high similarity with other fungal endoglucanases, especially with those of Humicola grisea and Fusarium oxysporum, on the basis of hydrophobic cluster analysis. The egI gene was expressed under the promoter of the phosphoglycerate kinase gene (PGK) in Saccharomyces cerevisiae. The transformed cells were able to secrete the enzyme efficiently in an active form.

Amino Acid Sequence↗
PubMed2000

Tissue doppler imaging of left and right ventricles in normal children.

Tissue Doppler imaging is a new ultrasound technology that derives measurements of contraction and relaxation velocities directly from the myocardium. However, data on myocardial velocities by using tissue Doppler imaging have not been established in normal children. In 48 normal children, myocardial velocities were measured using tissue Doppler imaging at three different sites (base, middle, and apex) in the left and right ventricles and the interventricular septum. In the left ventricular wall, the peak myocardial velocities during early diastole (peak E), during atrial contraction (peak A), and during systole (peak S) waves decreased gradually between the base and apical sites, whereas the ratio of E to A waves (peak E/A wave ratio) did not change among the 3 segments. Similar findings were obtained from the myocardial velocities in the right ventricle and the interventricular septum. A systolic and diastolic velocity gradient was also observed between the different ventricular walls. Significant correlations of the tissue Doppler parameters with age or heart rate were observed. In the left ventricle, the peak E wave demonstrated a stronger relation with age (r=0.77) than with heart rate (r=-0.65). The peak A wave did not change with age but correlated with heart rate. The peak E/A wave ratio showed a weaker relation with age (r=0.54) than with heart rate (r=0.62). The peak S wave was related to age (r=0.65) and to a lesser extent to heart rate (r= -0.51). Similar relationships of tissue Doppler parameters with age or heart rate were observed for the right ventricle and interventricular septum. The heterogeneous pattern and age- and heart-rate-related changes in normal myocardium demonstrated in this study must be taken into account when attempting to identify altered regional myocardial function with tissue Doppler echocardiography.

Adolescent↗
PubMed2000

Immunoliposome-mediated gene transfer into cultured myotubes.

We encapsulated marker genes, pRSV-lacZ or pRSV-luc, in immunoliposomes conjugated with antibody targeting laminin B2 in the basal lamina of myotubes. The immunoliposomes were incubated with matured non-proliferating myotubes differentiated from C2C12 myoblasts. We then evaluated the efficiency of gene transfection by measuring luciferase activity and beta-galactosidase staining. The immunoliposomes conjugated with the antibody specific for myotubes were three times as efficient as control immunoliposomes conjugeted with an antibody not specific for myotubes. However, the efficiency was no more than that by the cationic liposomes without the antibody. These results suggest that laminin B2 is not effective in enhancing the efficiency of gene transfection for non-proliferating myotubes. A specific antibody for surface antigen other than laminin B2 should be chosen in further studies.

Animals↗
PubMed2000

Distribution of acid sphingomyelinase in human various body fluids.

Enzyme activities of acid sphingomyelinase (ASM) were determined in various human cell-free body fluids, serum, cerebrospinal fluid, urine, salivary fluid, tear fluid, and synovial fluid, using assay buffers with or without Zn2+ -cation. Although ASM activity was not detected in the cerebrospinal fluid, the other fluids demonstrated significant enzyme activities of ASM. All ASMs detected in the fluids were stimulated by the addition of Zn2+ -cation, suggesting that those enzymes are secretory ASM derived from ASM gene. We suggest a possible enzymatic diagnosis of Niemann-Pick disease types A and B using those body fluids. Interestingly, salivary and tear fluids showed much higher activities of ASM than those of the other fluids. Because sphingolipids, especially sphingomyelin, are major constituents of a normal diet, especially, milk, eggs, and meat products, we suggest that ASM in the salivary gland may play an important role in the digestion of sphingomyelin in a normal diet.

Adult↗
PubMed2000

Direct production of allitol from D-fructose by a coupling reaction using D-tagatose 3-epimerase, ribitol dehydrogenase and formate dehydrogenase.

Allitol was produced from D-fructose via a new NADH-regenerating enzymatic reaction system using D-tagatose 3-epimerase (D-TE), ribitol dehydrogenase (RDH), and formate dehydrogenase (FDH). D-fructose was epimerized to D-psicose by the D-TE of Pseudomonas cichorii ST-24 and the D-psicose was subsequently reduced to allitol by the RDH of an RDH-constitutive mutant, X-22, derived from Klebsiella pneumoniae IFO 3321. NADH regeneration for the reduction of D-psicose by the RDH was achieved by the irreversible formate dehydrogenase reaction, which allowed the D-psicose produced from d-fructose to be successively transformed to allitol with a production yield from D-fructose of almost 100%. The reactions progressed without any by-product formation. After separation of the product from the reaction mixture by a simple procedure, a crystal of allitol was obtained in a yield exceeding 90%. This crystal was characterized and determined to be allitol by HPLC analysis, its IR and NMR spectra, its melting point, and optical rotation measurement.

Journal Article↗
PubMed1999

Tissue Doppler imaging in the normal fetus.

Tissue Doppler imaging is a new non-invasive method that derives measurements of relaxation velocities directly from the myocardium. This approach to studying myocardial velocities offers the potential for quantitative assessment of diastolic ventricular function. Data on myocardial tissue velocities in normal fetuses have not been established. We measured motion velocities of the left ventricular posterior wall, right ventricular anterior wall, interventricular septum along the long axis in 30 normal fetuses aged 19-38 weeks gestation (mean, 26.3+/-6.0 weeks). In all fetuses, peak myocardial velocities during early diastole (EW) and atrial contraction (AW) waves were recorded. The mean values for EW, AW, and E/AW of left ventricle were 5.4+/-1.7, 7.0+/-1.4 cm/s, and 0.77+/-0.19, respectively, and those of right ventricle were 5.5+/-1.5, 7.8+/-1.5 cm/s, and 0.70+/-0.14, respectively. The EW(4.1+/-1.0 cm/s) and the AW (5.3+/-0.8 cm/s) of the interventricular septum were significantly lower than those of the left and right ventricular walls (P<0.01). The EW and E/AW of the left ventricular wall increased significantly with increasing gestational age (r=0.81 and 0.85, respectively, P<0.01). Similar changes were observed in the myocardial velocities of the right ventricular wall. The EW and E/AW of the interventricular septum also increased significantly with age (r=0.63 and 0.78, respectively, P<0.01). However, AW of the interventricular septum showed little changes. In both ventricles, there were significant correlations between tissue Doppler E/AW and pulsed Doppler E/A (LV, r=0.56; and RV, r=0.60, P<0.01). Assessment of myocardial tissue velocities in fetuses is feasible with tissue Doppler imaging. Age-related alterations in tissue Doppler velocities may suggest age-related maturational changes in diastolic function.

Blood Flow Velocity↗
PubMed1999

Migratory basal ganglia lesions in subacute sclerosing panencephalitis (SSPE): clinical implications of axonal spread.

We report a boy with subacute sclerosing panencephalitis (SSPE) who exhibited parkinsonian symptoms four months after onset. The symptoms improved after administration of levodopa. One year after onset, bilateral symmetric lesions appeared in the substantia nigra and the putamen, as observed using magnetic resonance imaging. After a one-year interval, the lesions migrated to the bilateral caudate and the cerebellar dentate nuclei. The series of migratory legions, each of which was connected by axonal pathways originating from the substantia nigra, suggests axonal spread of the SSPE virus.

Adolescent↗
PubMed1999

Striatal perfusion of indomethacin attenuates dopamine increase in immature rat brain exposed to anoxia: an in vivo microdialysis study.

Using in vivo microdialysis and HPLC, we examined the effects of indomethacin on extracellular dopamine (DA) in the striatum of immature rats submitted to anoxia. Rat pups in two indomethacin groups received intrastriatal perfusion of either 1 mM or 5 mM indomethacin throughout the experiment. The DA level reached 1185+/-400% of the basal level during anoxia; in contrast, the peak levels of DA were only 307+/-63%, 153+/-35% in indomethacin groups (p<0.05). We consider that this suppression would be one of the mechanisms of the protective effect of indomethacin on hypoxic ischemic encephalopathy.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1999

Positron emission tomography in juvenile Alexander disease.

A 13-year-old boy with cervical kyphosis was diagnosed as having juvenile Alexander disease because of the typical MRI findings, abnormally elevated alphaB-crystallin and heat shock protein 27 in the cerebrospinal fluid. Positron emission tomography with 18F-fluorodeoxyglucose demonstrated hypometabolism in the frontal white matter corresponding to the areas with leukodystrophy. However, the overlying gray matter preserved normal glucose metabolism.

Adolescent↗