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Biomedical subjects

H Ohtsuka

Publications and source records attributed to H Ohtsuka.

At least 109 records · Page 6Linked to original sources
PubMed1991

Adenosine 3',5'-cyclic monophosphate-dependent protein kinase (A kinase) regulation of insulin receptor function: phosphorylation of insulin receptor with A kinase decreases the insulin binding activity.

The effect of phosphorylation of insulin receptor with adenosine 3',5'-cyclic monophosphate-dependent protein kinase (A kinase) on its insulin binding activity was investigated by using insulin receptors prepared from rat liver in vitro. A 95 KDa protein was phosphorylated by stimulation of insulin receptor kinase. This protein was also phosphorylated by A kinase. Analysis of phosphoamino acid showed that tyrosine residue(s) was phosphorylated by activation of insulin receptor kinase, whereas phosphoserine and phosphothreonine were dominantly generated by activation of A kinase. [125I] Iodoinsulin binding activity was decreased by prior phosphorylation of the receptor with A kinase. Scatchard analysis showed that the affinity for insulin was decreased by the phosphorylation with A kinase. Although the maximal activity of insulin receptor kinase was not affected by phosphorylation with A kinase, the insulin concentration which induced half maximal activity (ED50) of the receptor kinase was increased by the phosphorylation with A kinase. These results suggested that counter regulatory hormones whose actions are mediated by the generation of adenosine 3',5'-cyclic monophosphate regulate the insulin binding to the alpha subunit through phosphorylation of the beta subunit of insulin receptor.

Adenosine Triphosphate↗
PubMed1991

GRP (gastrin-releasing peptide)-containing nerves in the rat stomach and stress-induced depletion of their synaptic vesicles. An electron microscope study.

Gastrin-releasing peptide (GRP)-containing nerves are extremely numerous in the mucosa of the gastric body. Our previous study demonstrated that depletion of GRP from the nerves occurred in close relation to ulceration in the stomach. The present study deals with the ultrastructure of the GRP-immunoreactive nerves under normal conditions and its changes induced by conditions of stress. The immunoreactivity for GRP was recognized selectively in large cored vesicles in the swollen axoplasm of the nerves. The same axoplasm further revealed immunonegative small clear vesicles which were believed to contain acetylcholine. In materials where the GRP-immunoreactive nerves markedly decreased in number, both large and small synaptic vesicles were depleted from the nerves. These findings suggest that GRP and acetylcholine coexist in single nerves in the oxyntic mucosa, and that by nerve stimulation, they are coreleased into the lamina propria.

Acetylcholine↗
PubMed1991

Carbon monoxide-induced delayed amnesia, delayed neuronal death and change in acetylcholine concentration in mice.

We investigated the interrelationship of delayed amnesia, delayed neuronal death and changes in acetylcholine concentration induced by carbon monoxide (CO)-exposure in mice. In the test for retention of the passive avoidance task, amnesia was observed 5 and 7 days after CO-exposure when the mice were exposed to CO 1 day after training; in the case when the mice were exposed to CO 5 and 7 days before training, amnesia was also observed in a retention test given 1 day after training. The number of pyramidal cells in the hippocampal CA1 subfield was lower than that of the control 3, 5 and 7 days after CO-exposure. But the neurodegeneration in the parietal cortex, area 1, was not observed until 7 days after CO-exposure. The findings indicated that the amnesia and the neuronal death were produced after a delay when the mice were exposed to CO. In addition, the delayed amnesia was closely related to the delayed neuronal death in the hippocampal CA1 subfield. Moreover, [3H]glutamate and [3H]glycine binding sites did not change after CO-exposure but, 7 days after CO-exposure, the concentration of acetylcholine and the binding of [3H]quinuclidinyl benzilate in the frontal cortex and the striatum were found to have significantly changed, but those in the hippocampus did not show significant change. Therefore, we suggest that delayed amnesia induced by CO-exposure may result from delayed neuronal death in the hippocampal CA1 subfield and dysfunction in the acetylcholinergic neurons, in the frontal cortex, the striatum and/or the hippocampus.

Acetylcholine↗
PubMed1990

Deletion of human JK segments by site-specific recombination recognizing the conserved nonamer and heptamer sequences.

Mapping and partial sequencing of the productive K chain genomic DNA of FK-001 demonstrated a 1.8-kb deletion including the JK2, JK3, JK4, and JK5 segments. This deletion occurred between the heptamer recombination signal sequence of the JK2 segment and the heptamer-like sequence located 1.8 kb downstream of the JK2 segment. The recombination reaction kept the reciprocally joined signal sequences on the chromosome and deleted the intervening DNA segment. The cloned FK-001 K chain gene was expressed efficiently in mouse myeloma cells, demonstrating that the 1.8-kb deleted region conferred no functions for gene expression.

Animals↗
PubMed1990

N-acetyl-L-galactosaminuronic acid as an epitope common to the O-polysaccharides of Pseudomonas aeruginosa serotype A and H (Homma) recognized by a protective human monoclonal antibody.

We have established a human--mouse heterohybridoma cell line producing a human monoclonal antibody TS-3G2 (IgG gamma 1, K). This monoclonal antibody specifically bound to O-polysaccharides belonging to plural Pseudomonas aeruginosa Homma serotypes, A and H, in contrast to serotype-specific monoclonal antibody which exclusively bound to strains belonging to a single specific serotype. The binding affinity for serotype A strains was higher than that for serotype H strains. Competitive enzyme immunoassay experiments with O-polysaccharide preparations derived from IID 1001, NCTC 8505 (serotype A) and IID 1009 (serotype H) and their derivatives demonstrated that the N-acetyl-L-galactosaminuronic acid residue in O-polysaccharide was essentially involved in the epitope for TS-3G2. Furthermore, a 6-deoxy-hexosamine residue neighboring the reducing terminal of N-acetyl-L-galactosaminuronic acid residues was also concerned with the epitope to some extent. In the experimental infection model of normal mice, the monoclonal antibody TS-3G2 showed a protective activity against both strains of serotype A and H.

Animals↗
PubMed1990

Port wine stain: distribution patterns on the face and neck.

One hundred and three port wine stains, maximum length 5.0 cm or more in adults, and the length of the patient's thumb or more in children, on the unilateral side, were selected to be part of an analysis of port wine stain distribution patterns. Port wine stain lesions were evaluated, and similar lesion patterns were grouped together and outlined on a face map. Six major patterns were found: forehead (F), temporal (T), angular (A), labio-infraorbito-(angular) (L-O and L-O-A), labio-infraorbito-angulo-(forehead)-temporal (L-O-A-[F]-T) and jaw-neck (J-N). A wide-ranging, unilateral, or even bilateral port wine stain may be evaluated as a mixed form, which is composed of several standard patterns of port wine stains. The cause of port wine stains is also briefly discussed.

Adolescent↗
PubMed1990

Bilateral vermilion flaps for lower lip repair.

A more natural reconstructive procedure of the lower lip using bilateral vermilion flaps was applied in five patients with excellent results. The vermilion defects were about two-fifths to three-fifths. In three patients, the vermilion defect was repaired using bilateral vermilion flaps alone. In the remaining two patients, a narrow horizontal lip defect was repaired by bilateral vermilion flaps and a subcutaneous V-Y advancement flap of the lower lip. A single vermilion flap or bilateral vermilion flaps are considered to be of great value for vermilion reconstruction because of the inherent elasticity and common anatomic unit. The postoperative scars are not remarkable at all. A long and narrow horizontal lip defect (perhaps within 1.5 cm downward from the vermilion border) may be effectively repaired by the combination of vermilion flap(s) and a V-Y advancement flap without sacrificing any additional healthy tissue.

Adolescent↗
PubMed1990

The relationship between solar keratoses and squamous cell carcinomas among Japanese.

Between 1976 and 1988, 135 patients with solar keratosis (SK) and 53 patients with squamous cell carcinoma (SCC) on the sun-exposed skin, but without apparent preceding diseases such as burn scars, chronic radiodermatitis, chronic arsenic poisoning, or xeroderma pigmentosum, were encountered. Sixteen of the SCC patients also had SK on other areas of sun-exposed skin. There were 31 SCC patients also showing SK (SK-SCC) and 22 SCC not showing SK (DN-SCC) within the same histologic sections. The mean ages of the patients with SK-SCC and with DN-SCC were similar. Metastases to regional lymph nodes were observed in 5 SK-SCC patients, of whom 3 died of the disease, and in 5 DN-SCC patients, of whom 4 died of the disease. The five-year post-operative survival rates were 70% in SK-SCC and 74% in DN-SCC; the ten-year post-operative survival rates were 70% in SK-SCC and 44% in DN-SCC.

Aged↗
PubMed1990

Intrauterine Chlamydia trachomatis infection in a premature infant.

Intrauterine Chlamydia trachomatis infection was strongly suspected in a premature infant born in the 32nd week of gestation. The membranes were artificially ruptured at the time of delivery. This infant showed a high titer of specific IgM antibody to Chlamydia trachomatis at one hour after birth. He showed mild respiratory distress and was treated with oral erythromycin for three weeks. He was discharged home at the age of 46 days.

Chlamydia Infections↗
PubMed1990

Electrical catheter ablation for drug-refractory sustained ventricular tachycardia with old myocardial infarction--a case report.

We performed electrical catheter ablation (ECA) in a patient who had old myocardial infarction and drug-refractory sustained ventricular tachycardia (VT). ECA using 100J to the earliest activation site and the pace-mapping site failed to prevent the VT. ECA using the same energy to the site at which mid-diastolic potential was recorded during tachycardia could successfully ablate the VT. Therefore the site of energy delivery was important in VT with old myocardial infarction.

Aged↗
PubMed1990

Effects of beta-hydroxy butyric acid on insulin binding to its receptor and on autophosphorylation of the receptor.

We examined the effects of beta-hydroxy butyric acid (B-OH-butyrate) on insulin binding to its receptor and on autophosphorylation of the receptor in vitro. The affinity of isolated rat adipocyte insulin receptors was significantly increased by B-OH-butyrate at neutral pH. Similar results were obtained with soluble insulin receptors prepared from hepatocytes. Autophosphorylation of insulin receptor, however, was not affected by OH-butyrate at neutral pH. These results suggested insulin resistance in ketoacidosis is not caused by an interaction between B-OH-butyrate and the insulin receptor.

3-Hydroxybutyric Acid↗
PubMed1990

[A case of aorto-coronary bypass surgery in a hypophysectomized male patient].

A 53-year-old hypophysectomized male patient who had been on adjuvant therapy with cortizol and thyroxin, underwent aorto-coronary bypass surgery for angina pectoris with 3 vessel obstruction. Following revascularization surgery, he had an uneventful course until 8th post-operative day, when he experienced about of unconsciousness which was relieved by intravenous hydrocortizon supplement. Simultaneously complicated bradycardia and peripheral coldness were considered to be due to lowered serum T3 and T4 values. By the time the thyroid function stabilized, three times as much as preoperative dosage of thyroxin had to be administered for 34 days. The control of the hypothyroidism plays an important role in the postoperative management of the patient with panhypopituitarism after the cardiac surgery.

Angina Pectoris↗