Biomedical subjects

Y Morita

Publications and source records attributed to Y Morita.

At least 19 recordsLinked to original sources

PubMed1992

Expression and possible function of glucose transporter protein GLUT1 during preimplantation mouse development from oocytes to blastocysts.

A micro-Western analysis method both sensitive and quantitative enough to analyze oocytes and embryos is developed. GLUT1 protein is present in mouse oocytes and preimplantation embryos and levels are increased by fertilization and with time in ensuing embryonic development; the levels were 20-fold greater in blastocysts than in unfertilized oocytes. Similar increases were observed in glucose uptake by oocytes and embryos, suggesting that they may depend on GLUT1 expression. These results suggest that GLUT1 expression may explain a switch in substrate preference of the embryo from pyruvate to glucose during preimplantation development.

Animals↗

PubMed1992

Interstitial deletion of chromosome 16q: 16q22 is critical for 16q- syndrome.

Partial deletion of 16q is rare; to our knowledge only 12 cases have been published. Fryns et al. [Hum Genet 38:343-346, 1977] described the first of these cases and proposed a new clinical entity. Our patient was a girl and had many minor anomalies of the kind often observed in 16q- syndrome. Severe failure to thrive due to emesis and diarrhea were also observed. High resolution banding methods showed that the chromosome constitution of the patient was 46,XX,del(16)(q22.1q22.3). This suggests that 16q22 is critical for the syndrome.

Chromosome Deletion↗

PubMed1992

cDNA cloning of rice lipoxygenase L-2 and characterization using an active enzyme expressed from the cDNA in Escherichia coli.

A full-length cDNA of rice lipoxygenase L-2 was cloned from 3-day-old seedlings. The identity of the clone was determined by amino acid sequencing of selected peptides of the purified enzyme and immunological characterization of an active enzyme that was produced from the cDNA in Escherichia coli by cultivation at 15 degrees C. The nucleotide sequence showed a strong bias toward G and C in the selection of nucleotides, especially at the third position of the codons (93% G/C). The complete amino acid sequence of the enzyme was deduced from the nucleotide sequence. The molecular mass of the enzyme was calculated to be 96,657 Da based on 865 amino acids. The amino acid sequence shares similarity with those of dicot lipoxygenases throughout the enzyme at a level of 50%. A hydropathy profile calculated from the amino acid sequence resembled those of dicot lipoxygenases, suggesting conservation of the secondary structure of these enzymes. The active enzyme, expressed in Escherichia coli, was characterized for pH dependence of the enzyme activity, intramolecular specificity, heat stability and Km. The enzyme had the same properties as the L-2 enzyme that was isolated from seedlings, but differed from the lipoxygenase L-3 isolated from mature plants.

Amino Acid Sequence↗

PubMed1992

Stem cell factor has histamine releasing activity in rat connective tissue-type mast cells.

Stem cell factor (SCF) was documented to be involved in the growth of mast cells controlled by fibroblasts. We tested the effect of recombinant rat SCF on degranulation from rat peritoneal mast cells (connective tissue-type mast cells: CTMC). SCF induced histamine release (approximately 20% of total histamine content) in a dose-dependent fashion. The release response was relatively rapid and reached a maximum within 5 min. The release showed total dependence on the presence of extracellular phosphatidylserine (PTS). These results reveal that SCF has histamine releasing activity in CTMC.

Animals↗

PubMed1992

Effects of an eight-hour advance of the light-dark cycle on sleep-wake rhythm in the rat.

We observed effects of an 8-h advance of the light-dark (LD) cycle on the sleep-wake rhythm in the rat. On the day phase-advanced, rapid eye movement (REM) sleep increased with its enhanced diurnal amplitude. Non-REM (NREM) sleep gradually increased in parallel with the decrease of its diurnal amplitude. Although the acrophase of NREM sleep gradually advanced after the phase advance, that of REM sleep did not significantly change. We confirmed that diurnal rhythm of REM sleep was hardly shifted and dissociated from the rhythm of NREM sleep under the eight-hour advance of the LD cycle in the rat.

Animals↗

PubMed1992

Inhibition of IgE-mediated histamine release by myosin light chain kinase inhibitors.

Wortmannin, a specific inhibitor of myosin light chain kinase (MLCK) blocked IgE mediated histamine release from rat basophilic leukemia cell (RBL-2H3) and human basophils dose-dependently. Its IC50 was 20 nM for RBL-2H3 cells and 30 nM for human basophils. There was complete inhibition at the concentration of 1 microM. Wortmannin inhibited partially the A23187 induced histamine release from RBL-2H3 cells (40% inhibition at 1 microM). This inhibition was not accompanied by any significant effect on cytosolic free calcium concentration [( Ca2+]i). KT5926, another MLCK inhibitor, inhibited histamine release comparably with wortmannin and blocked to some degree the increase of [Ca2+]i in RBL-2H3 cells. Thus, the phosphorylation of myosin seems to be involved in signal transduction through Fc epsilon RI.

Alkaloids↗

PubMed1992

Verbal versus non-verbal visual evoked potentials: Kanji versus line drawings.

Cortical areas related to perception of verbal and non-verbal stimuli were studied using VEPs. Kanji characters, line drawings (LD), or a blank were displayed. Verbal VEPs were obtained by subtracting the blank-VEPs from the Kanji-VEPs, and non-verbal VEPs by subtracting the blank-VEPs from the LD-VEPs. Both the verbal and non-verbal VEPs showed a negative peak (100-300 msec) focally over bilateral occipital, posterior temporal and parietal areas, and a positive peak diffusely over frontal halves. Differences between the non-verbal from the verbal VEPs showed an initial peak (100-200 msec) focally over bilateral occipital and posterior temporal areas, followed by a peak (200-300 msec) focally over bilateral posterior temporal areas. The frontal areas diffusely showed peaks at 100-200, 200-300 and 300-400 msec. Left-right asymmetries of both the verbal and non-verbal VEPs showed peaks between 100 and 300 msec over posterior temporal, parietal, and occipital areas. Left-right asymmetries of the subtraction to the non-verbal from the verbal VEPs showed a peak (100 msec) over occipital and parietal areas, and a broader peak over posterior temporal area (100-200 msec). Bilateral occipital, posterior temporal, and parietal areas are focally activated by the two perceptions (100-300 msec), while frontal areas are activated diffusely. Further, different processes may be focally involved between the hemispheres over occipital (100-200 msec) and posterior temporal (100-200 and 200-300 msec) regions. Initial left-right asymmetries of the subtracted VEP between the two perception would occur over occipital and parietal areas (100 msec) and last for 200 msec over posterior temporal area.

Acoustic Stimulation↗

PubMed1992

Relationship between eye movements and oneiric behavior in cats.

The relation between oneiric behavior and rapid eye movements (REMs) in paradoxical sleep (PS) without muscle atonia was analyzed in cats. Most isolated REMs were related to orienting behavior, whereas most REM bursts were related to generalized body movements (jumping, attacking, etc.). Only isolated, high amplitude REMs had any possibility of corresponding to visual images in dreams. From these findings we propose the existence of both dream-related and nondream-related REMs even in animals.

Animals↗

PubMed1992

Signal transmission from pineal photoreceptors to luminosity-type ganglion cells in the lamprey, Lampetra japonica.

In order to study the signal transmission from pineal photoreceptors to luminosity (achromatic)-type ganglion cells of the lamprey, Lampetra japonica, the electrical activity of these cell groups was investigated using intra- and extracellular electrodes. By intracellular recording, it was shown that the photoreceptor cells responded to flashes of light with hyperpolarizations, and the ganglion cells also hyperpolarized with concurrent suppression of spike discharges. Concerning the slow membrane potentials, the light intensity-response relationships of both cell groups followed the Naka-Rushton hyperbolic function. The intensity range over which the ganglion cells responded was broader than that of the photoreceptors. The spectral sensitivity curve of the luminosity-type ganglion cell coincided with that of the photoreceptor, showing a peak sensitivity at 525 nm. Membrane resistance of the ganglion cells increased during light stimulation. These results suggest that the luminosity-type ganglion cell receives and integrates signals from photoreceptors with various light sensitivities, having a peak spectral sensitivity at 525 nm. The synaptic mechanism from the photoreceptors to the ganglion cell is a type of disfacilitation.

Animals↗

PubMed1992

Alveolar hydatid disease of the liver: computed tomography and transabdominal ultrasound with histopathological correlation.

The appearances of alveolar hydatid disease of the liver (AHDL) on computed tomography (CT) and ultrasound (US) were retrospectively compared with histopathological appearances in 67 patients with 100 separate lesions. The radiological features were correlated directly with the pathological specimens obtained from each patient. We conclude that the CT appearances are more specific, but that US has a role to play in mass screening in endemic areas, and intraoperatively.

Adolescent↗

PubMed1992

Dietary ascorbic acid depresses plasma and low density lipoprotein lipid peroxidation in genetically scorbutic rats.

The effects of dietary ascorbic acid on plasma lipoprotein and liver lipid peroxide concentrations were examined using ODS od/od rats with a genetic defect in the ability to synthesize ascorbic acid. ODS od/od rats were fed purified diets supplemented with 0 to 300 mg ascorbic acid/kg diet for 21 d. An ascorbic acid-free diet induced body weight loss, depleted ascorbic acid in the plasma and increased thiobarbituric acid-reactive substances in the plasma and liver as compared with rats fed ascorbic acid supplemented diets and with normal ODS +/+ rats fed the ascorbic acid-free diet. Increasing ascorbic acid concentration in the diet inhibited the development of these ascorbic acid deficiency symptoms in a dose-dependent manner. The dietary requirement of ascorbic acid to maintain normal body weight gain and plasma lipid peroxide concentrations was approximately 150 mg ascorbic acid/kg diet. On the other hand, even 300 mg ascorbic acid/kg diet was insufficient to maintain a hepatic concentration of ascorbic acid comparable to that in the liver of ODS +/+ rats. The lipid peroxide concentration in plasma LDL and liver was significantly elevated in ODS od/od rats fed the ascorbic acid-free diet. Supplementing the diet with 300 mg ascorbic acid/kg kept those concentrations within the normal ranges seen in the ODS +/+ rats.

Animals↗

PubMed1992

Three-dimensional structure of soybean beta-amylase determined at 3.0 A resolution: preliminary chain tracing of the complex with alpha-cyclodextrin.

The three-dimensional structure of a complex of soybean beta-amylase [EC 3.2.1.2] with an inhibitor, alpha-cyclodextrin, has been determined at 3.0 A resolution by X-ray diffraction analysis. Preliminary chain tracing showed that the enzyme folded into large and small domains. The large domain has a (beta alpha)8 super-secondary structure, while the smaller one is formed from two long loops extending from the beta 3 and beta 4 strands of the (beta alpha)8 structure. The interface of the two domains together with shorter loops from the (beta alpha)8 structure form a deep cleft, in which alpha-cyclodextrin binds slightly away from the center. Two maltose molecules also bind in the cleft. One shares a binding site with alpha-cyclodextrin and the other is situated more deeply in the cleft.

Binding Sites↗

PubMed1992

Haemopoietic growth factors induce human basophil migration in vitro.

Accumulation of basophils in inflammatory sites is an important aspect of the late-phase allergic reaction involving skin and upper and lower airways, suggesting the existence of mechanisms for basophil migration. Because haemopoietic growth factors have been shown to stimulate various functions of human basophils, we tested the ability of haemopoietic growth factors to migrate basophils in vitro. Both IL-3 and granulocyte-macrophage colony-stimulating factor (GM-CSF) induced migration of purified normal basophils (purity c. 80%) in a dose-dependent fashion at picomolar concentrations, while granulocyte (G)-CSF, macrophage (M)-CSF, and IL-4 had no effect at all. Chequerboard analyses indicate that migratory activity of both factors are chemokinetic. These results suggest that local production of both factors during allergic reactions might potentially play an initial role in the recruitment of basophils from the circulation to sites of inflammatory reactions.

Antibodies↗

PubMed1992

A mosaic case of isodicentric chromosome 18.

A case of mosaicism of isodicentric chromosome 18 is reported. Dicentric chromosome 18 occurs rarely and only five cases of isodicentric chromosome 18 have been documented. A high resolution banding method revealed that the karyotype of the patient was mos 46,XX/46,XX idic(18)(pter-->q21.3::q21.3-->pter), and the ratio of normal and abnormal clones was 1:1. The clinical manifestations, resembling those of trisomy 18 syndrome, were affected by both partial trisomy 18pter-->q21.3 and partial monosomy 18q21.3-->qter.

Child↗

PubMed1992

Effectiveness of 6-month intermittent administration of natural human interferon-alpha against non-A non-B chronic hepatitis.

Interferon (IFN) was administered intermittently for 6 months to the patients with non-A non-B chronic hepatitis (CHNANB), and the effectiveness of the treatment for improving the hepatic function was evaluated. Of 26 patients with CHNANB, 16 received intermittent IFN therapy (IFN group), and 10 were treated by conventional therapies without IFN (non-IFN group). All patients were observed for 1 year. IFN was administered once a day at 3 MU in principle (1 MU in some patients and 6 MU in 1 patient) daily for 1 week immediately after the beginning of the therapy and 3 times a week for the subsequent 6 months at the outpatient clinic. The patients were followed up for at least 6 months after completion of the treatment. In the IFN group, the serum GPT level normalized in 11 (68.8%) of the 16 patients 1 year after the beginning of the treatment. In these 11 patients (normalized group), HCV-RNA was negative or became negative in 3 of the 6 patients in whom the serum HCV-RNA could be examined. Histological grades of inflammation in the liver were also markedly alleviated in the normalized group. The hepatic function did not normalize in any of the 10 patients in the non-IFN group. These findings indicate that IFN therapy is useful for CHNANB.

Alanine Transaminase↗

PubMed1992

Squamous cell carcinoma of unknown origin in middle mediastinum.

We report a rare case of squamous cell carcinoma located in the middle mediastinum as a solitary mass. Histologically, lymphatic tissues remained together with nests of squamous cell carcinoma which were occupying the greater part of the mass. Examinations of the whole body failed to detect a primary site of the squamous cell carcinoma. It is considered that the carcinoma cells reflect metastasis from a primary-unknown carcinoma (most likely TO lung squamous cell carcinoma) or that they originated from benign epithelial inclusions in a mediastinal lymph node.

Carcinoma, Squamous Cell↗

PubMed1992

Hemopoietic growth factors regulate the survival of human basophils in vitro.

Human basophils were purified from normal peripheral blood, using density gradient followed by negative panning selection. We tested the effects of hemopoietic growth factors on the survival of these basophils in vitro. In the absence of exogenous factors, basophils (purity greater than 90%) decreased in number rapidly. At day 7 only 11% of the cells remained alive in cultures; less than 1% of cells survived at day 14. Interleukin (IL)-3 maintained numbers of viable cells; cell viability was 67% at day 7 and 45% at day 14. Granulocyte-macrophage (GM)-colony-stimulating factor (CSF) exhibited slight effect on the survival; 33% of cells remained at day 7. Other growth factors including granulocyte (G)-CSF, macrophage (M)-CSF, and IL-4 had no significant effect on the survival of basophils at all. Morphological and functional characterization of cells maintained by IL-3 revealed that they belonged to the basophil lineage. These observations indicate that normal basophils possess functional receptors for IL-3 and GM-CSF and that both factors modulate immediate- and delayed-type hypersensitivity reactions by prolonging the life span of basophils.

Basophils↗

PubMed1992

Mouse IL-3 induces histamine release from mouse peritoneal mast cells.

In this study, we have attempted to determine whether mouse peritoneal mast cells released histamine in response to IL-3. Recombinant mouse (m)IL-3 induced histamine release from mouse peritoneal mast cells in a dose-dependent fashion. Histamine release did not occur in the absence of phosphatidyl serine (PS), and was dependent on PS concentrations. The release was 14.3 +/- 3.8 and 43.5 +/- 11.5% (mean +/- SEM, n = 5) at 1 nM IL-3 in the presence of 10 and 20 micrograms/ml of PS. Calcium was required for the response, and in the absence of calcium, significant histamine release was not observed. The kinetics were slower than those of anti-IgE-induced response. IL-3-induced histamine release reached a peak within 15 min, while that by anti-IgE reached 80% of the maximum in 3 min. Lower concentrations of IL-3, which failed to directly induce histamine release, did not enhance anti-IgE-induced histamine release. Other cytokines, including mIL-4, mIL-5, m-granulocyte-macrophage colony-stimulating factor, human (h)IL-1 alpha, hIL-1 beta and hIL-8, neither induced histamine release nor enhanced anti-IgE induced histamine release. IL-4 had no capacity to enhance IL-3-induced histamine release. These results suggest that locally produced IL-3 might modulate mast cell-related inflammation through histamine release from mast cells.

Animals↗