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Biomedical subjects

S Uchida

Publications and source records attributed to S Uchida.

At least 433 records · Page 24Linked to original sources
PubMed1989

The "antidementia drug", pantoyl-GABA, increases choline acetyltransferase activity in mouse brain.

Studies were made on the effects of in vivo administration of an "anti-dementia drug", pantoyl-GABA, on choline acetyltransferase (ChAT) activity in mouse brain. Male ICR mice were treated intraperitoneally with 500 mg/kg of pantoyl-GABA, once a day, for various periods. Then they were killed, and the ChAT activities of their cerebral cortex, hippocampus and striatum were measured. Results showed that ChAT activity increased significantly in the cerebral cortex and hippocampus from day 5 and 7, respectively, of treatment, but did not increase in the striatum even after treatment for 14 days. The kinetics of ChAT activity were investigated in tissues from the cerebral cortex and hippocampus of mice treated with the drug for 7 days. Drug-treatment increased the Vmax value, but did not affect the Km values for choline and acetyl-CoA. These results indicate that long-term treatment with pantoyl-GABA enhanced ChAT activity, without altering the affinity of the enzyme for either substrate.

Animals↗
PubMed1989

Effect of serum fractions obtained from cancer patients by double filtration plasmapheresis combined with natural tumor necrosis factors and cyclophosphamide on murine pulmonary metastases.

We investigated the effects of fractionated sera obtained from cancer patients by double filtration plasmapheresis (DFPP) plus antitumor agents on murine pulmonary metastasis. Fractions of the sera, in combination with natural human tumor necrosis factors (nTNF) and cyclophosphamide (Cy), were systemically administered to Lewis lung carcinoma-bearing mice. When the second filtrate (a plasma fraction containing substances composed of smaller molecular weight compounds) combined with low-dose nTNF (1,000 U/kg) and Cy (250 micrograms/kg) was administered to the mice, the degree of metastasis was significantly suppressed compared with the control group (p less than 0.01). In contrast, the discarded fluid (a plasma fraction containing larger molecular weight compounds) combined with the same doses of nTNF and Cy caused little inhibition of metastasis. Also, the discarded fluid significantly suppressed natural killer activity compared with normal sera (p less than 0.01). The results suggested that DFPP combined with nTNF and Cy is an efficient procedure to remove immunosuppressive factors from the sera of cancer-bearing hosts, to enhance the host antitumor immunity, and to suppress tumor proliferation.

Animals↗
PubMed1989

[Sequential changes in blood pressure and electrocardiographic findings over seventeen years in three different regions in Okayama Prefecture].

The sequential changes in blood pressure and electrocardiographic findings of populations living in three districts of Okayama prefecture, with differing environments and life styles, were analyzed during the seventeen year period from 1966 to 1982. Furthermore, factors influencing the causes of mortality among these populations were evaluated in 790 males and 1, 118 females (total 1,908), aged from 35 to 65 years at the beginning of the survey (1966). During the survey period 94 subjects moved out of the district and 210 subjects died, so that in 1982, 975 subjects (61.1%) could be examined. Cerebrovascular disease, cancer, and cardiac disease were the major causes of death in all these districts. A higher mortality from cerebrovascular disease was recorded in the mountainous district, with harsh weather and living conditions, in contrast to the other two lowland district. There was no significant difference in mortality due to cardiac disease among the three districts. In the mountainous district, the incidence of hypertension, especially systolic hypertension, was higher than in the other two districts throughout the whole of this survey. However, after 1980, the difference in the incidence of hypertension among the districts diminished sequentially. The incidence of hypertension was higher in the elderly than in younger subjects. However, even this age difference in incidence was seen to diminish sequentially, (especially for diastolic hypertension). The ratio of the number of people who were actually treated to the population who needed hypertensive therapy increased gradually, and in 1978 there was no significant difference concerning this ratio among the three districts. Finally over 80% of the subjects who qualified for antihypertensive therapy were treated continuously. The appearance ratio of abnormal ECG findings, (Minnesota Code, Code 3, Code 3 + 4, 5 and especially Code 4 and 5), increased in proportion to the increase of blood pressure in the hypertensive group. The sequential appearance ratios for the borderline hypertension and stage I hypertension groups showed an inverse relationship to that of the normal group. However the appearance ratios of stage II & III hypertension groups increased sequentially with no relation to that of the normal group. Subjects whose ECG showed ST-T changes without subjective symptoms apparently increased sequentially in all districts. The incidence ratios of angina pectoris and myocardial infarction showed no significant sequential changes. These results suggested that high blood pressure (both systolic and diastolic) was controlled fairly well in all age groups by therapy.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1989

Ultrasonography of benign gastric ulcers. Characteristic features and sequential follow-ups.

Ultrasonography was performed for 15 patients with gastric ulcers, after tap water ingestion using 5-MHz and/or 7.5-MHz transducers. Sonographic signs of gastric ulcer were classified as gastric wall edema associated with ulcer crater (six cases) and gastric wall edema only (nine cases). The latter nine included two cases of perforation of gastric ulcers that were depicted as gastric wall edema associated with fluid collection. Ultrasonography proved useful for detecting benign ulcerations and can be used to supplement follow-up examinations, but it cannot replace endoscopy and contrast radiography.

Adult↗
PubMed1989

[Application of isocyanate separating agent for acrylic resin].

The most widely used agents for separating acrylic resin from gypsum molds are the water-soluble alginates, which produce a very thin water- and organic solvent-insoluble calcium alginate film on the gypsum surface. In the present study, a new type of separating agent, an isocyanate type coating agent, was developed and it's properties were investigated. This coating agent is composed mainly of trimethylol-propane-tolylenediisocyanate and ethyl-acetate, with a small amount of bis-tributyl-tin oxide as catalyst. At first, a thin film was formed on the surface by application of the agent, and then alkyl-phosphate was applied to this film to ensure easy separation of the cured resins from the molds. The molds treated with this separating agent had a glossy, hard surface. The surface of the cured resins treated in this way was glossier and smoother than that of resin treated with the water-soluble alginates.

Acrylic Resins↗
PubMed1989

[A case of lung metastasis of thyroid cancer with endobronchial polypoid growth].

A case of a 73-year-old woman, complaining of exertional dyspnea and hemoptysis, is reported. About twenty years earlier, she had been diagnosed as having a thyroid carcinoma and had undergone a partial thyroidectomy. Bronchoscopic findings showed an endobronchial polypoid tumor which obstructed the intermediate bronchus almost completely. The polyp was about 3cm in length and protruded from the entrance of the middle lobe bronchus. The histologic findings revealed it to be a metastasis of the papillary thyroid carcinoma. After a polypectomy, the hypoxemia and dyspnea showed remarkable improvement.

Aged↗
PubMed1989

Clinical application of cascade filtration combined with glassbead adsorbents in cancer patients.

Cascade filtration (CF) was applied to patients with advanced cancers. To selectively remove immunosuppressive factors with molecular weight lower than albumin, adsorbents combined with CF were examined. Among 11 kinds of adsorbents, glassbead adsorbents with pore size 100A were the most effective in adsorbing such substances. Clinically, a column packed with glassbead adsorbents was concomitantly used with CF. The second filtrate was passed through the column and returned to the patient. The removal rate of immunosuppressive substances with molecular weight lower than albumin was only 20% by CF alone, but more than 50% by CF combined with glassbead adsorbents. Clinical symptoms such as severe back pain and general malaise were drastically improved during and after therapy. These results suggest that CF combined with glassbead adsorbents is an effective adjunctive modality to cancer therapy.

Adsorption↗
PubMed1988

The SH-H subgroup of cardiac M2 receptors (M2 alpha) inhibits adenylate cyclase activity.

Muscarinic receptors in the guinea-pig heart seem to consist entirely of M2 receptors, but are coupled with several responses including inhibition of adenylate cyclase activity. On the other hand three affinity states (SH, H and L) can be distinguished in cardiac membranes with muscarinic agonists such as carbachol. We showed previously that the three agonist binding states were the sum of two equilibria (SH-H and H-L subgroup), both regulated by GTP-binding protein(s). In this study we determined which subgroup was responsible for the inhibitory effect of muscarinic M2 receptors on adenylate cyclase activity. The ED50 values for this response of four muscarinic agonists, acetylcholine, carbachol, pilocarpine and oxotremorine corresponded with the binding KD values of H (acetylcholine and carbachol) and LO/P (pilocarpine and oxotremorine) sites. After alkylation of spare receptors, the ED50 value of carbachol was changed from 4.3 to 5.6 microM, which corresponded with the KD value of the H site. Furthermore, the four agonists were almost fully active when membrane preparations were pretreated with propylbenzilylcholine mustard (PrBCM) in the presence of carbachol to destroy the H-L subgroup, whereas after pretreatment with PrBCM and atropine, which alkylated both types of subgroups evenly, the decrease in the number of receptors was proportional to the decrease in the inhibitory effect on adenylate cyclase activity. These results suggest that only the SH-H subgroup (M2 alpha) is responsible for the inhibitory action of muscarinic receptors on adenylate cyclase activity in the heart.

Adenylyl Cyclase Inhibitors↗
PubMed1988

Preventive action of quisqualic acid against grayanotoxin-induced suppression of locomotor activity in mice.

Grayanotoxin-III (GTX-III) is a constituent in leaves of Pieris japonica D. Don which exhibits, in vitro, the ability to open voltage-sensitive sodium channels in various excitable tissues. Effects of systemic administration of GTX-III were studied in vivo using Std-ddy mice. Salivation, vomiting and paralysis of the hind paws invariably occurred in mice injected intraperitoneally with 0.1 or 0.25 mg/kg of GTX-III. The writhing response to an intraperitoneal injection of acetic acid was considerably diminished by pretreatment of animals with the toxin. The grayanoid also caused a profound attenuation of the response to caudal compression, while inducing no significant alteration of that to thermal injury. Pretreatment with GTX-III resulted in a significant decrement of the time required for loss of the righting reflex induced by pentobarbital, with a concomitant delay in recovery. Mice injected with the toxin exhibited a significant and restorable suppression of coordination, and a long-lasting suppression of spontaneous locomotor activity in both horizontal and vertical directions. Neither tetrodotoxin (1-5 micrograms/kg, i.p.) nor Ro15-1788 (1-5 mg/kg, i.p.) prevented the GTX-III-induced suppression of locomotion. Atropine (5-10 mg/kg, i.p.) failed to antagonize the GTX-III-induced suppression but protected against salivation induced by the toxin without affecting other symptoms. Intracerebroventricular injection of quisqualic acid (0.5 microgram), one of the agonists for central glutamate receptors, but not that of tetrodotoxin (5 ng) prevented the GTX-III-induced suppression of horizontal movement. These results suggest that GTX-III may elicit its depressant action on horizontal locomotion possibly through interacting with central glutamatergic neurons rather than activating voltage-sensitive sodium channels in the brain. Possible involvement of muscarinic cholinergic neurons in the GTX-III-induced salivation is also suggested.

Analgesics↗