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Biomedical subjects

T Ota

Publications and source records attributed to T Ota.

At least 289 records · Page 16Linked to original sources
PubMed1985

Self-excitation in a porous membrane doped with sorbitan monooleate (Span-80) induced by an Na+/K+ concentration gradient.

The electrical potential across a fine-pore membrane doped with sorbitan monooleate (Span-80) imposed between aqueous solutions of NaCl and KCl was studied. It was found that this system showed rhythmic and sustained oscillations of electrical potential between the two aqueous solutions. These oscillations were attributed to the change of permeability of Na+ and K+ across the membrane, which originated from the phase transition of Span-80 molecules within the fine pores. Impedance measurement across the membrane also suggested a change in permeability. It was found that this membrane exhibited the property of differential negative resistance. In relation to this, it was shown that Na+ and K+ have different effects on the aggregation of Span-80 molecules. The mechanism of oscillation is discussed in relation to the ability of Span-80 molecules to behave as a dynamic channel through the membrane. This oscillatory phenomenon is interesting because in biological nervous membranes a difference between the concentrations of Na+ and K+ across the membranes is essential for excitability.

Hexoses↗
PubMed1985

[Aortic dissection presenting aortic regurgitation induced by diastolic prolapse of an intimal flap into the left ventricle: a case report].

A case of aortic dissection associated with aortic regurgitation which was induced by diastolic prolapse of an intimal flap into the left ventricular outflow tract was reported. This 57-year-old man, referred for evaluation of sudden onset of chest oppression and a heart murmur, was hypertensive for several years. His admission blood pressure was 184/44 mmHg, and a systolic ejection murmur and a diastolic decrescendo murmur were audible along the left sternal border. Two-dimensional echocardiography revealed an intimal flap in the markedly enlarged aortic root. The intimal flap moved posteriorly in systole and anteriorly in diastole, and prolapsed into the left ventricular outflow tract during diastole. Associated with the movement of the intimal flap, an aortic cusp was shifted from its original position to the left ventricular outflow tract in diastole. Aortography disclosed type I aortic dissection and severe aortic regurgitation. After medical treatment for four months, the patient underwent a Bentall surgical procedure and recovered. Impaired coaptation of the aortic valve induced by diastolic prolapse of the intimal flap into the left ventricular outflow tract is a newly encountered echocardiographic finding in proximal aortic dissection.

Aortic Dissection↗
PubMed1984

Oscillation of electrical potential in a porous membrane doped with glycerol alpha-monooleate induced by an Na+/K+ concentration gradient.

The electrical potential across a fine-pore membrane doped with glycerol alpha-monooleate and separating aqueous solutions of 0.5 M NaCl and 0.5 M KCl was studied. It was found that this system showed rhythmic and sustained oscillations of electrical potential. These oscillations may be due to the phase transition of glycerol alpha-monooleate molecules within the fine pores. In relation to this, it is shown here that Na+ and K+ have different effects on the aggregation of glycerol alpha-monooleate. This oscillatory phenomenon is very interesting because in biological nervous membrane an Na+/K+ concentration difference across the membrane is essential for excitability.

Glycerides↗
PubMed1984

Frequency of criteria-defined borderline patients among the first-visit patients at a psychiatric clinic.

Five trained psychiatrists evaluated 330 first-visit patients aged from 12 to 30 at a psychiatric outpatient facility using the DSM-III criteria (Axis-I and Axis-II). Seven cases were diagnosed as definite Borderline Personality Disorder and six cases as definite Schizotypal Personality Disorder. Hence, we had a total of 13 criteria-defined borderline patients (3.9%). Discussions were held on some methodological problems involved in collecting information and making diagnostic judgments.

Adolescent↗
PubMed1984

Enzyme defect in a case of tyrosinemia type I, acute form.

We determined the activities of tyrosine aminotransferase (TAT, EC 2.6.1.5), p-hydroxyphenylpyruvate oxidase (p- HPPA oxidase, EC 1.14.2.2) and fumarylacetoacetate fumarylhydrolase ( FAH , EC 3.7.12) in cytosol of the liver and kidney tissues obtained at autopsy from a case of hereditary tyrosinemia type I. Values were compared with those from a control group of autopsied tissues from three adults and six children, who had died of other causes. In tyrosinemia, these three hepatic enzyme activities were all decreased: TAT showed approximately 35%, p- HPPA oxidase 11%, and FAH 60% of the corresponding control values. On the other hand, kidney enzymes in tyrosinemia revealed that FAH was most significantly decreased to approximately 14% of the control activity. Km values for substrate--determined for p- HPPA oxidase and FAH --were not different between the patient and controls, suggesting no altered properties of these enzymes. We conclude that in the present case of hereditary tyrosinemia type I, the activities of p- HPPA oxidase in liver and FAH in kidney were most strikingly affected. This fact may in part explain the deteriorated metabolism of tyrosine observed in this patient.

4-Hydroxyphenylpyruvate Dioxygenase↗
PubMed1982

[Studies on the safe limit of variable decelerations during labor].

Ninety neonates who presented variable decelerations during labor were divided into two groups, according to the one-minute Apgar scores of greater than or equal to 8 and 7 less than or equal to. Only neonates of singleton pregnancies and cephalic presentations of 34 weeks gestation or more were included in the study. Several parameters of this fetal heart rate (FHR) pattern and the presence or absence of meconium staining were compared. Followings were found to be statistically significant. 1) The duration of the variable deceleration (less than 2 hours). 2) The FHR deceleration/uterine contraction ratio (less than 80%). 3) The absence of meconium staining. An effort was made to establish safe limits of variable decelerations. These are shown in parentheses. Based on both these data and findings of others, a multifactorial scoring system named a variable deceleration score was proposed for the proper management of this FHR pattern. Five variables were selected for the system. These were: The duration of variable decelerations, the FHR deceleration/uterine contraction ratio, the duration and amplitude of dips, and the presence or absence of meconium staining. The system scores from 0 to 2 for each of five factors, and was designed to be able to predict depressed neonates with the numerical increase of the score.

Female↗