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Biomedical subjects

Y Aoki

Publications and source records attributed to Y Aoki.

At least 739 records · Page 41Linked to original sources
PubMed1984

[A case of hepatocellular carcinoma (acute abdominal type) misdiagnosed as acute appendicitis and satisfactorily treated by a two-stage operation].

A 66-year-old man was admitted because of right lower abdominal pain and was operated on for acute appendicitis on March 12, 1983. It was found that his appendix was not inflamed, but a bleeding tumor was encountered in the posterior segment of the liver. Bleeding was controlled by suturing the liver above the tumor. Postoperative celiac angiography revealed many daughter tumors scattered in, but restricted to, the right lobe of the liver. The patient was treated by transcatheter arterial embolization combined with transcatheter arterial infusion of lipiodol and Adriamycin on April 25. Subsequently, a curative operation (right hemihepatectomy) was performed on May 24. The patient is still alive without recurrence 6 months after the resection. In case of ruptured hepatocellular carcinoma, it appears to be better to perform a two-stage operation with careful estimation of functional reserve of the liver, and to conduct transcatheter arterial embolization between operations to prevent the growth of the tumor during that period.

Abdomen, Acute↗
PubMed1984

Plasma level of diethylcarbamazine in jirds and hamsters.

The relation between the dosage and plasma level of diethylcarbamazine (DEC) in jirds and hamsters was examined by gas-liquid chromatography. When the drug was given intraperitoneally to jirds at 100 mg/kg body weight, the plasma level rose rapidly and reached the maximum level (20-25 micrograms/ml) at 10 minutes and afterwards fell quickly to undetectable level at 4 hours. Even if larger dosage (300 mg/kg) was given, DEC was eliminated completely from the blood circulation within 8 hours. When the same dosages of DEC were given intraperitoneally, the DEC levels remained 2-4 hours longer in the blood of hamsters than in the blood of jirds. DEC given by stomach intubation at 100 mg/kg remained detectable much longer in hamsters (8 hrs) than in jirds (2 hrs). A repeated doses schedule did not show a tendency for the drug to accumulate. DEC was excreted in the urine and feces, but the total amount of drug excreted without metabolic changes was only about 8% of the given dosage. The majority of unmetabolized DEC was excreted in the urine within 0-12 hours.

Administration, Oral↗
PubMed1983

Gel permeation, ion-exchange and reversed-phase columns for separation of metallothioneins by high-performance liquid chromatography-atomic absorption spectrophotometry.

Metallothioneins were separated on three kinds of HPLC column that differ in separation principle: gel permeation, ion exchange and reversed phase. Elution of the columns at neutral to weakly basic buffer conditions prevented dissociation of the metals, and the metals bound to metallothioneins were quantitatively eluted out. The metals in the eluate were continuously determined on an atomic absorption spectrophotometer by introducing the eluate directly to the nebulizer tube. Prerequisites for the on-line separation-detection system are discussed.

Animals↗
PubMed1983

A specific radioimmunoassay for corticotropin releasing factor (CRF) using synthetic ovine CRF.

This newly developed specific radioimmunoassay for corticotropin releasing factor (CRF) had a sensitivity range of 25 pg/tube to 4 ng/tube. Intra and interassay coefficient of variation were 4.6% and 9.8%, respectively. Rat median eminence extracts showed a parallel dose response curve with synthetic ovine CRF and a significant cross reaction was not evident with other tested neuropeptides. The highest mean levels of CRF were found in the median eminence (6.61 ng/mg protein). Considerable amounts of CRF were found in the arcuate nucleus, paraventricular nucleus, dorsomedial nucleus, suprachiasmatic nucleus and ventromedial nucleus. The immunoreactive CRF of the rat medial basal hypothalamus coeluted with bioassayable CRF and with iodinated CRF on Sephadex G-75 chromatography. The results indicate that rat hypothalamus contains a CRF similar to ovine CRF.

Animals↗
PubMed1983

Role of medullasin in granulocytes in the development of inflammation. I. Phlogistic activity and the effect on functions of macrophages and granulocytes.

Injection of a small amount of medullasin protease (20 micrograms) into the skin of guinea pigs or rabbits caused inflammation characterized by severe injury to endothelial cells in venules and by infiltration of a large number of macrophages. Medullasin inhibited macrophage chemotaxis in vitro, stimulated granulocyte chemotaxis, and potentiated the production of superoxide by macrophages. These results indicate that medullasin in granulocytes plays an important role in the development of inflammation.

Animals↗
PubMed1983

Effects of thyrotropin-releasing hormone on catecholamine concentration in various structures of the rat brain.

In an attempt to identify the site of TRH-action in the central nervous system (CNS), we have measured catecholamine levels in discrete brain regions of rats after an intravenous administration of TRH or a long-term intraventricular administration of TRH using Alzet's osmotic minipump. An intravenous administration of 50 micrograms TRH caused a rapid increase in dopamine (DA) concentration in the septal nucleus and then returned to the basal level at 30 min after injection. The concentration of DA in the septal nucleus after the long-term TRH intraventricular administration was also significantly higher than that in the controls. These results indicate that a long-term intraventricular administration of TRH as well as a bolus intravenous injection of TRH may affect the release or metabolism of DA in the septal nucleus.

Animals↗
PubMed1983

Characterization of rat hypothalamic corticotropin-releasing factor by reversed-phase, high-performance liquid chromatography with synthetic ovine corticotropin-releasing factor as a marker.

Reversed-phase, high-performance liquid chromatography (HPLC) was carried out to characterize rat hypothalamic corticotropin-releasing factor (CRF) using synthetic ovine CRF as a marker. Samples were injected onto a stainless steel column (4 X 250 mm) packed with Hitachi gel 3053. The column was eluted using a gradient elution of increasing acetonitrile concentration, in a mixture of NaCl-HCl at a flow rate of 1.0 ml/min, monitoring the column effluent at 220 nm with an UV detector. Fractions eluted every 1-2 min were collected and lyophilized for subsequent CRF bioassay and radioimmunoassay. When various neuropeptide mixtures including synthetic ovine CRF were injected onto the column, synthetic ovine CRF was separated from the other neuropeptides with a gradient of 0-60% acetonitrile in 0.1 M NaCl-0.01 N HCl or 0-08% acetonitrile in 0.05 M NaCl-0.01 N HCl. The median eminence extracts showed two main peaks of CRF bioactivity on HPLC. One (small CRF) coeluted with arginine vasopressin and oxytocin markers, and the other (big CRF) appeared near the position of synthetic CRF and was divided into two peaks. One coeluted with synthetic ovine CRF and the second eluted after synthetic CRF, showing high CRF activity. Three or four peaks of CRF immunoreactivity appeared on HPLC and the main peak appeared after synthetic ovine CRF marker. Our results suggest that rat CRF is different from ovine CRF, and the total lipophilicity of amino acid residues of rat CRF may be higher than that of ovine CRF.

Animals↗