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Biomedical subjects

H Chiba

Publications and source records attributed to H Chiba.

At least 235 records · Page 13Linked to original sources
PubMed1986

Saccadic eye movements in tracking, fixation, and rest in schizophrenic and normal subjects.

Horizontal eye movements were recorded electrooculographically during two different eye fixation tasks, during an eyes-closed waking state, and during eye tracking on a sinusoidally moving target in 16 chronic schizophrenics and in 12 normal subjects. The relationship between saccadic eye movements during tracking and in the other experimental situations was investigated. The intensities of eye fixation were successively decreased from Experiment I (eye fixation on a stationary target) through Experiment II (eye fixation on an imagined spot in the dark) to Experiment III (eyes closed in the dark, no cue for eye fixation), in that order. The frequency of saccades increased as the intensities of fixation decreased from Experiment I to Experiment III in both schizophrenic and normal groups. It was demonstrated that the frequency of saccades was higher in schizophrenics than in normal subjects in all of the experimental conditions. Some correlations were found between the increased frequency of saccades seen during eye tracking and the similar increases seen in eyes-fixated or eyes-closed states in schizophrenic subjects. It is suggested that the increased saccades seen during eye tracking and in other experimental conditions in schizophrenics are related to a deficit of nonvoluntary attention, due to a failure of an inhibitory mechanism.

Adult↗
PubMed1986

Isolation and characterization of cDNA encoding rabbit reticulocyte 2,3-bisphosphoglycerate synthase.

We have isolated and sequenced a cDNA clone containing the entire coding region of rabbit reticulocyte 2,3-bisphosphoglycerate (DPG) synthase. The cDNA was verified by translation of the hybridization-selected RNA and by demonstrating identity of the deduced amino acid (aa) sequence to the sequences of CNBr peptides of the purified enzyme. The aa sequence of the enzyme was homologous to the reported sequence of the human enzyme [Haggarty et al., EMBO J. 2 (1983) 1213-1220], especially in the N-terminal half (aa 1-142). Northern blot analysis of rabbit reticulocyte poly(A)+ RNA revealed a single species of mRNA with about 1700 nucleotides.

Amino Acid Sequence↗
PubMed1986

[Exercise tolerance in mitral stenosis and chronic obstructive pulmonary disease: evaluation by anaerobic threshold and radionuclide ventriculography].

Serial radionuclide ventriculography was performed using a newly developed "real-time" system, and left ventricular ejection fraction (LVEF), right ventricular ejection fraction (RVEF), stroke volume (SV), and cardiac output (CO) were measured during graded supine exercise in five patients with mitral stenosis (MS), in five patients with chronic obstructive pulmonary disease (COPD) and in five healthy subjects. Simultaneous pulmonary gas exchange analysis permitted determining the anaerobic threshold, which is the point during incremental exercise when lactate begins to accumulate in the blood. LVEF at the anaerobic threshold was not significantly changed in any patient groups and in healthy subjects, but RVEF at the anaerobic threshold was lower in COPD and MS patients as compared with healthy subjects. In MS, SV during exercise was reduced at the anaerobic threshold, but not in COPD or in healthy subjects. In conclusion, reduced working capacity is related to decreased RVEF in both COPD and MS, but the inhibited increase in CO during exercise is also important for the working capacity in MS.

Adult↗
PubMed1984

Isolation of human erythropoietin with monoclonal antibodies.

Human erythropoietin was isolated from urine of aplastic anemic patients in a high yield with a simple purification procedure using an immunoadsorbent column of monoclonal antibodies and a Sephadex G-100 column. About 6 mg of erythropoietin was isolated from 700 liters of urine and the specific activity was estimated to be 81,600 units/mg of protein with an in vivo 59Fe incorporation assay method, using starved rats. Activity measurement of the extracts from sliced gels after sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the Western blotting technique revealed heterogeneity of the isolated erythropoietin, which is probably caused by variable amounts of carbohydrates attached to the polypeptide chain. Thirty amino acids in the NH2-terminal portion of the isolated hormone were sequenced.

Anemia, Aplastic↗
PubMed1984

Primary aldosteronism due to adrenal cortical carcinoma.

We report a rare case of primary aldosteronism due to adrenal cortical carcinoma. Endocrinological data showed an isolated excess of aldosterone production without any associated increase in other steroids. Adrenal scintigraphy, which has not been described in cases of primary aldosteronism due to adrenal cortical carcinoma, revealed an increased uptake of the radionuclide into the affected adrenal gland without suppression in the contralateral gland.

Adrenal Cortex↗
PubMed1984

Specific immobilization of an enzyme by monoclonal antibody: immobilization of guinea pig liver transglutaminase.

A simple method for enzyme immobilization using a monoclonal antibody raised against the enzyme was studied, taking guinea pig liver transglutaminase as an example. This method consists of two steps; a conjugation of monoclonal antibodies, which bind with the enzyme without inhibitory effect on the activity, with agarose gel bead supports, and immobilization of enzyme proteins onto the conjugated monoclonal antibodies through the antigen-antibody immunoreaction. The following are the advantages of this method. (i) Activity recovery after the immobilization was very high, (ii) enzyme proteins in crude enzyme preparation could be immobilized specifically, and (iii) immobilized enzymes could be replaced easily by fresh enzyme proteins through a urea-buffer treatment.

Acyltransferases↗
PubMed1984

Hybridomas for production of monoclonal antibodies to human erythropoietin.

Human urinary erythropoietin has been highly purified by a combination of conventional purification methods and immunoadsorbent columns packed with hybridoma-produced antibodies against contaminants that seemed difficult to separate from erythropoietin by the usual means. By using the partially purified erythropoietin as an antigen, three hybridoma clones have been obtained that secrete monoclonal antibodies against erythropoietin. One of the clones has been quite stable, with a rapid growth rate and high production of antibody. Western blotting technique with monoclonal antibodies revealed occurrence of two species of erythropoietin. The monoclonal antibody will be useful as a probe for the purification of erythropoietin and for further studies of the hormone and its mechanism of action.

Animals↗
PubMed1984

[Rhythmic slow wave observed on nocturnal sleep encephalogram in children with idiopathic nocturnal enuresis].

Whole-night sleep polygraph by removing the first-night effect was recorded for 15 cases of idiopathic nocturnal enuresis and 10 cases of normal control, thereby, review was made on the relation between sleep and etiology of nocturnal enuresis as well as the appearing characteristics of rhythmic slow wave. (hereinafter referred to R.S.W.). Thus the following results were obtained. Both groups of nocturnal enuresis and normal control showed no significant difference under the same experimental conditions for the rate of encephalogramic sleep stage. Nocturnal enuresis was observed in nearly the same number of cases at any stage of sleep except Stage 1 (hereinafter referred to as S), and there were many cases in the second and third sleep cycles. At the time of occurrence of nocturnal enuresis, 6-7 Hz R.S.W. continued as long as 15-40 seconds in NREM-sleep. Also, 3-5 Hz R.S.W. was observed in REM sleep. R.S.W. was observed even in normal cases, while its incidence was high in the cases of nocturnal enuresis, and the decrease was observed with advancement of age, however, the decrease was delayed in the cases of nocturnal enuresis. R.S.W. was provoked reactively against the stimuli such as the change in the electro-encephalogramic sleep stage and body movements. On the other hand, there was an inhibitory tendency of the changes in heart rate and respiration during the appearance of R.S.W. By the above result and the resemblance between R.S.W. and DR theta, R.S.W.(ABSTRACT TRUNCATED AT 250 WORDS)

Child↗
PubMed1983

Nuclear binding and sedimentation properties of two activated forms of glucocorticoid-receptor complexes from rat mammary glands.

Mammary cytoplasmic glucocorticoid-receptor complexes, which had been exposed to a high concentration of ammonium sulfate, were found to be separated into two receptor forms, consisting of DNA-cellulose-bound and non-DNA-cellulose-bound receptors. Experiments under cell-free conditions revealed that not only the DNA-cellulose-bound receptor but also the non-DNA-cellulose-bound receptor have binding abilities to nuclei and to nuclear chromatin. In sucrose density gradient centrifugation, the non-DNA-cellulose-bound receptor sedimented at higher sedimentation coefficients than the DNA-cellulose-bound receptor under all the salt conditions tested. These data strongly suggest that in the mammary glucocorticoid receptor system there exist at least two activated receptor forms with different conformations.

Animals↗
PubMed1983

Role and induction of 2,3-bisphosphoglycerate synthase.

2,3-Bisphosphoglycerate accumulates in mammalian erythrocytes, where it facilitates the supply of oxygen to the tissues by binding to hemoglobin. Regulatory properties of 2,3-bisphosphoglycerate synthase and phosphatase are discussed. The 2,3-bisphosphoglycerate concentration was shown to rise linearly along with the hemoglobin level during erythroid differentiation. The accumulation of 2,3-bisphosphoglycerate was primarily attributable to an increase in 2,3-bisphosphoglycerate synthase. Antibody-binding studies showed that the increased activity is achieved solely through an increase in the amount of enzyme. It was shown that 2,3-bisphosphoglycerate synthase was synthesized in nucleated erythroid precursor cells and also in anucleated reticulocytes. The mRNA of this protein appears to be fairly stable in reticulocytes. Coordinate expression of hemoglobin and 2,3-bisphosphoglycerate synthase was found during dimethylsulfoxide-induced differentiation of Friend erythroleukemia cells. 2,3-Bisphosphoglycerate rose concomitantly.

2,3-Diphosphoglycerate↗