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Biomedical subjects

Y Morimoto

Publications and source records attributed to Y Morimoto.

At least 523 records · Page 29Linked to original sources
PubMed1982

[The influence of pentobarbital and Y-9179 on regional cerebral blood flow and infarction size in the middle cerebral artery occlusion model in cats (author's transl)].

Following permanent occlusion of the middle cerebral artery (MCA) in cats, the effect of delayed administration of pentobarbital (PBT) and a novel imidazole derivative (Nizofenone or Y-9179) on the regional cerebral blood flow (rCBF) was studied. The rCBF was measured for one week by the hydrogen clearance technique without anesthesia. The overall effects of these drugs on histological changes were also assessed. Twenty-four animals, in which platinum electrodes were chronically implanted in the ten predetermined positions, were divided into following three groups. The control, PBT and Y-9179 groups received the vehicle, PBT (25 mg/kg/day) and Y-9179 (6.25 mg/kg/day), respectively. Drug administration was started 30 min after MCA occlusion and continued for three days. In the affected hemisphere of the animals which survived for one week, histological examination revealed ischemic lesions composed of the marginal, reactive and central zones. The infarction ratio calculated as the ratio of the damaged area to the whole hemispheric area was significantly smaller in the drug treated groups than in the control. In the Y-9179 group, the reduction of the area comprizing the central and reactive zones was particularly prominent. There were no apparent differences in the time-course of the rCBFs between the control and Y-9179 groups. Each channel showed reduction of the rCBF following MCA occlusion. Although slight fluctuations of the rCBF were seen during the first three to four hours, the initially dropped rCBF remained stable in both groups. In the PBT group, on the other hand, an increase of the rCBF took place following the administration of the drug in the area where the rCBF was initially reduced less than about 40 ml/100g/min after MCA occlusion. Most of the electrodes showing such an increase in the rCBF topographically corresponded to the reactive or boundary zone. In the control group, vasogenic edema characterized by the perivascular exudation of plasma fluid was prominent in the periphery of the central zone as well as in the inner layer of the reactive zone. Such changes were almost absent in the Y-9179 group, whereas it was more evident and close to the control in the PBT group. So far as the correlation between the course of the rCBF and the final histological outcome was examined, there was no evidence indicating the beneficial effect of the redistribution of the rCBF by PBT. Y-9179 had no significant action on the course of the rCBF but its anti-edema effect might be related to its cerebral protective action. The mechanism of cerebral protection by PBT or Y-9179 needs further clarification.

Animals↗
PubMed1982

[Effect of acetyllactoylcholine-1,5-naphthalene disulfonate on the motility of stomach].

The effect of TM-723 on the motility of stomach was investigated by using the electromyogram, extraluminal strain gauge force transducer in dog and by measuring the human gastric emptying time. Three mongrel dogs were equipped with two bipolar electrodes on the serosal surface of the antrum and single bipolar electrode and single strain gauge on the surface of the body. Both the peristaltic spike discharge and contractile activity were recorded during 30 minutes before and 60 minutes after administration of TM-723 1 mg/kg, 3 mg/kg and 5 mg/kg, iv. The peristaltic spikes were suddenly disappeared on administration of TM-723 and after then, recurrent peristaltic spikes were recognized with prolonged interval and increased propagation velocity for about four minutes. The contractile activity increased with the administration of TM-723 for a minute. Gastric emptying time were measured on four healthy men by using of the test meal containing 300 muCi of 99mTc-DTPA before and after administration of TM-723 50 mg per os. The following results were obtained that three of four men had accelerated emptying time and one had no remarkable changes after taking TM-723. These studies suggest that TM-723 activates the motility of the stomach.

Acetylcholine↗
PubMed1982

[Change of pattern of gastric emptying after selective proximal vagotomy].

The patterns of gastric emptying after selective proximal vagotomy (SPV) and SPV with pyloroplasty (SPV + D) were studed using a liquid labelled with 99mTc-DTPA. By means of on-line computer facility, it was possible to analyse the relative role of the Whole stomach and the antrum within the overall frame work of gastric emptying. In the time/activity curve of the whole stomach, all of 3 groups emptied in exponential curve. Comparing with normal subjects, SPV subjects were tending to empty slowly, while SPV + D subjects were tending to empty rapidly. In the time/activity curve of the antrum, normal and SPV + D subjects had two types of emptying--one was represented in the decreasing curve and another was represented in the increasing-decreasing curve. While SPV subjects had only one type of emptying which was represented in the increasing-decreasing curve. From a consideration of the pattern of gastric emptying curve, SPV subjects had two different emptying states compared with normal subjects--one was the delay of entering the antrum from the fundic side of stomach, and the other was that effective antral emptying did not readily start. While SPV + D kept more neally normal gastric emptying that it of SPV.

Adult↗
PubMed1981

Biomedical applications of magnetic fluids II. 1) preparation and magnetic guidance of magnetic albumin microsphere for site specific drug delivery in vivo.

Magnetic guidance of magnetic albumin microsphere for site specific delivery was investigated in mice and rats. After intravenous injection in mice, magnetic microspheres with 1 and 3 micrometer diameter size were localized and retained in the target-site (lung) by application of two permanent magnets to the lungs. Injection into the renal artery in rats also indicated that the 1-micrometer microspheres were concentrated in the kidney by a magnetic field. When the magnets were not applied, however, the microspheres following intravascular injection were concentrated mainly in the liver, regardless of the route of administration. Such preferential localization by magnetic means suggested that magnetic albumin microspheres could become effective drug carriers with site specificity for the delivery of chemotherapeutic agents in cancer therapy.

Animals↗
PubMed1981

Spectrophotometric analysis for fluorouracil in biological fluids.

Fluorouracil (5-fluorouracil; 5-FU) is a monoanion at pH = 10 and forms an ion-pair complex with a quaternary alkylammonium ion. De Leenheer and co-workers [2] reported that the ion-pair complexes might be quantitatively extracted from aqueous solutions into organic solvents, and they spectrophotometrically determined the concentration of 5-FU. But as their method used column chromatography, it was cumbersome and time-consuming. Here we present a more rapid chemical assay of 5-FU by modifying the principle of their method. The applicability of this method was shown by determining the plasma and tissue levels of 5-FU in mice.

Animals↗
PubMed1980

[The development of a sensitive radioimmunoassay for H-TSH and its clinical application (author's transl)].

Using a commercially available h-TSH RIA kit (Daiichi), a sensitive RIA method was developed. When pooled serum from patients with active Graves' disease was used as a carrier, combined applications of a delayed addition of 125-I TSH and utilization of X2 diluted anti-TSH antibody resulted in the consistent detection of 0.156 microunits/ml level of serum TSH. Further, 0.078 microunits/ml level could also be detected when 200 microliter of serum samples were applied. However, usage of 200 microliter sample volume should be determined after further studies concerning possible non specific effects of human serum. Assay results of 29 patient sera by the sensitive assay correlated quite well (r = 0.953, Y = 0.97X-0.06) with those by the regular assay. Serum TSH in all of the 20 normal subjects were detectable and ranged from 0.31 to 3.2 microunits/ml giving mean values of 1.48 +/- 0.65 (s.d.) microunits/ml. Values less than 0.156 microunits/ml were observed in patients with untreated Graves' disease, acute stage of subacute thyroiditis, and panhypopituitarism, and in postoperative cancer patients under suppressive doses of T-4. In conclusion, this sensitive TSH RIA made clear discrimination of low and normal serum TSH possible, and the clinical application of this method was considered quite useful.

Graves Disease↗
PubMed1980

Biomedical applications of magnetic fluids. i. Magnetic guidance of ferro-colloid-entrapped albumin microsphere for site specific drug delivery in vivo.

Magnetic guidance of magnetic albumin microsphere for site specific drug delivery was investigated in vivo. After intravenous injection in mice, magnetic microspheres localized in the site (lung) at which two permanent magnets were placed. Injection into the renal artery in rats also indicated that the microspheres were concentrated at the kidney by a magnetic field. When magnet was not applied, however, the microspheres were concentrated mainly in the liver. Such preferential localization by magnetic means suggested that magnetic albumin microspheres could become effective drug carriers with site specificity for the delivery of chemotherapeutic agents in cancer therapy.

Albumins↗