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Biomedical subjects

Y Yoshida

Publications and source records attributed to Y Yoshida.

At least 1,063 records · Page 59Linked to original sources
PubMed1991

Effect of recirculation on exacerbation of ischemic vascular lesions in rat brain.

Using electron microscopy, we investigated the small arteries and veins in ischemic lesions induced by occlusion of the ostium of the middle cerebral artery in 42 rats. We observed endothelial denudation in the small arteries of rats receiving occlusion for greater than 6 hours. When the occluding cylinder was removed to allow for reperfusion, however, 2 hours of occlusion was sufficient for endothelial denudation to occur. Medial smooth muscle cells seemed to be more vulnerable to ischemia than endothelial cells because ultrastructural changes in the former cells preceded endothelial denudation. Moreover, endothelial denudation definitely exacerbated vascular changes so that medial necrosis appeared to be complete beneath the denuded areas, allowing erythrocytes, platelets, and exogenous tracers to penetrate into the cytoplasm of smooth muscle cells. These arterial lesions seemed to be repaired 10 days after removal of the occluding cylinder following 2 hours of occlusion. On the other hand, small veins in the ischemic lesion did not show endothelial denudation or medial necrosis. Our study suggests that arterial changes in ischemic lesions play a role in exacerbating the brain edema caused by recirculation after ischemia.

Animals↗
PubMed1991

Adsorption of negatively charged microcapsules to a poly(2-hydroxyethylmethacrylate)/polyamine graft co-polymer surface.

The electrokinetic properties of artificial particles--microcapsules--were compared with those of the rat lymphocyte sub-populations, T and B cells, and similar results were obtained. The affinity of the microcapsules to the polyamine graft co-polymer, which was claimed to be capable of separating the cells efficiently, was measured and it revealed that not the magnitude of the surface negative charge and the kind of dissociable groups, but the balance of the anionic and cationic charges on the microcapsule surface played a key role in their adsorption to the co-polymer.

Adsorption↗
PubMed1991

Active principle of swine prostate extract: I. Isolation of active principle activating prostatic acid phosphatase and its effect on testosterone uptake of the prostate in castrated rats.

There have been several reports concerning the therapeutic effect of an extract from animal prostates on benign prostatic hypertrophy. Previously, we reported that the swine prostate extract (PE) had the activity to enhance human prostatic acid phosphatase (PAPase) activity in vitro, and to increase the muscular tonicity of the urinary bladder by directly acting upon vesical muscles, suggesting that PE have an activity to elevate the intravesical voiding pressure in vivo. In the present study, it was attempted to isolate such an active principle of PE as activates human prostatic acid phosphatase (PAPase). The finally purified PE (PPE) was assessed as to some physico-chemical and pharmacological properties. 1) PPE was found to be a peptide with a molecular weight of about 8,800, composed largely of neutral amino acids (approximately 70%) and few of aromatic amino acids. 2) PPE activated PAPase in a dose-dependent fashion, resulting in an increase of the enzyme activity approximately twice in a dose of 2 X 10(-5) g/ml of PPE. Furthermore, PPE recovered PAPase activity dose-dependently from the 50% inhibition by 2 X 10(-3) M L-tartaric acid. 3) In castrated rats, the 3H-testosterone uptake of the prostate was significantly suppressed by the oral administration of PPE. PPE might be one of active principles of PE for the therapeutic effect on prostatic hypertrophy.

Acid Phosphatase↗
PubMed1991

Active principle of swine prostate extract: II. Effect of a peptide isolated from swine prostate extract on rat prostate.

Previously, we purified a substance from swine prostate extract (PE) that had been reported to have therapeutic effect on benign prostatic hypertrophy. The purified substance (PPE) suppressed 3H-testosterone uptake into the prostate in castrated rats. The present study was carried out to examine the effect of PPE on the weight of accessory sexual organs including the prostate and biochemical parameters in the prostate of normal and/or castrated and testosterone-treated rats. 1) In normal rats, the p.o. administration of PPE daily for a total of 30 days did not affect the prostate weight, but reduced the citric acid content in the prostate. The treatment had little or no influence tissue O2 uptake, aconitase activity or isocitrate dehydrogenase activity in the prostate. 2) In castrated and testosterone-treated rats, the p.o. treatment with PPE for 15 or 30 days reduced the weight of the prostate as well as the total citric acid, DNA and RNA contents in prostatic tissue. However, these biochemical parameters per tissue weight were not obviously affected except for the citric acid content. These findings suggest that PPE is one of the active principals of PE for the therapeutic efficiency on benign prostatic hypertrophy, probably due to its suppressive effect on excessive uptake of androgen by the prostate.

Aconitate Hydratase↗
PubMed1991

Electrophoretic studies on serum proteins in cows with traumatic pericarditis.

Diagnostic significance of electrophoretic findings of serum protein in cows with traumatic pericarditis was evaluated. Affected cows were classified into 3 groups according to autoptical findings: fibrinous, sero-fibrinous, and purulent types. Slight hypoprotenemia, moderate hypo-albuminemia, slight hyper-alpha globulinemia and tendency of hyper-beta globulinemia were commonly observed in the affected cows. The level of gamma globulin tended to be lower in the cows with fibrinous or sero-fibrinous, and higher in purulent pericarditis, than the level in healthy cows. In the serum protein electropherograms of the cows with fibrinous or sero-fibrinous pericarditis, there was pathognostic pattern composed of slender albumin, acute shape of alpha globulin with a broad rising accompanied by double peaks and with main peak migrating toward the albumin side, tendency of rising beta globulin fraction, and large indentation between beta and gamma fractions. These findings except for the slender albumin fraction, however, was not or poorly observed in purulent pericarditis. Electrophoretic findings were subacute inflammatory pattern with non-selective serum protein losing in fibrinous or sero-fibrinous, and chronic inflammatory pattern in purulent pericarditis.

Alpha-Globulins↗
PubMed1991

[Binswanger's disease with normal pressure hydrocephalus. Case report].

A 72-year-old hypertensive male was hospitalized with progressive gait disturbance (small step gait), urinary incontinence, and dementia. Computed tomography (CT) showed ventriculomegaly with periventricular lucency. T2-weighted magnetic resonance imaging revealed wide periventricular high-signal intensity and small infarctions in the basal ganglia. CT cisternography demonstrated ventricular stasis and convexity stasis of the contrast medium. Continuous intracranial pressure monitoring showed increased B wave percentage, low pressure volume index, and high outflow resistance. These findings indicated the coexistence of normal pressure hydrocephalus. After ventriculoperitoneal shunting, gait disturbance was greatly improved and urinary incontinence disappeared. The development of Binswanger's disease may be partially due to disturbed cerebrospinal fluid (CSF) dynamics. The possible pathophysiology of CSF dynamics in relation to Binswanger's disease is discussed. Detailed investigations of CSF dynamics are important in patients with Binswanger's disease, especially in the early stage.

Aged↗
PubMed1991

An enzyme (beta-D-N-acetylglucosaminidase) released from the decidua to maternal plasma prior to the onset of labor.

Changes in the activity of beta-N-acetylglucosaminidase (E.C. 3.2.1.30; NAG), a lysosomal marker enzyme, in the maternal plasma and utero-placental tissues during late pregnancy and parturition were examined in order to determine if lysosomal enzymes participate in the cervical ripening. NAG activity in the plasma gradually increased as gestation advanced, to reach a maximum 3-4 days before the spontaneous onset of labor, and remaining at this level until the second stage. The activity measured in decidua and amnion obtained from the women who had undergone routine repeat cesarean section after labor onset was lower than in those before the onset. Since the decidua was much heavier than the amnion, it was concluded that NAG was released to the maternal circulation mainly from the decidua and only partly from the amnion. Our data revealed that lysosomal enzyme release occurs prior to the onset of labor, and that NAG may play a role primarily in the ripening of the cervix rather than in the onset of labor, by hydrolysing GAGs in the uterine cervix.

Acetylglucosaminidase↗
PubMed1991

[Relationship between morphological and functional changes in the stomach with aging].

The authors investigated the relationship between morphological changes and functional changes of the stomach with ageing, especially in term of change of gastric emptying in 92 healthy subjects. We checked the difference in chronological age and the stomach age in these subjects (in order to assess these subjects). The morphological change was evaluated by extent of atrophic gastritis in endoscopical atrophic border and histological findings of biopsy specimens, and the functional change was evaluated by maximal acid output in gastric secretion. Atrophic gastritis was expanded and maximal acid output was significantly reduced with ageing. From these results we confirmed that there was no difference between the chronological age and the stomach age and the quality of these subjects was very good. Gastric emptying was investigated by the acetaminophen method. In spite of ageing, gastric emptying was almost constant in these healthy subjects.

Adult↗
PubMed1991

Epidemiological studies on host animals of tsutsugamushi disease in Korea.

Epidemiological studies on host rodents of tsutsugamushi disease were carried out during the period of July-September 1990 at nine localities of central Korea. Among total 111 wild rodents trapped by the modified Sherman live traps, 103 were Apodemus agrarius (92.8%), seven were Crocidura lasiura (6.3%) and one was Microtus fortis (0.9%), showing 24.0% of trapping rate in winter, 11.7% in spring, 11.2% in summer and 12.0% in autumn. Out of 103 A. agrarius 84 were parasitized by chiggers, showing 81.6% of the infestation rate and 43.0 of the chigger index. The antibody positive rate of A. agrarius sera to Rickettsia tsutsugamushi was significantly variable by locality, being in the range of 0-78.6%. The seasonal change of the antibody positive rate at Dorai 5-ri, Goyang-gun was 75.8% in average during November-March, decreased to 30.3% in April and further decreased to 13.3% in average during May-August. Among 33 antibody positives, 31 were Karp strain and two were Gilliam. Seven Crocidura lasiura sera showed all negative. R. tsutsugamushi organisms were isolated from three A. agrarius out of 94 mice tested, showing 3.2% of the infection rate.

Animals↗
PubMed1991

[Dipole tracing method analysis for source of auditory brainstem response (wave V) in two normal hearing subjects].

The location and vector moment of the equivalent current dipoles of ABR (wave V) evoked by unilateral acoustic stimuli were estimated in normal adults with the Dipole Tracing (DT) Method. The ABR's were recorded through 21 electrodes arranged according to the international 10-20 standard. The DT method is based on a realistic head shape with uniform volume conductor and individual differences of the skull were corrected for afterwards. The 3-D dipole locations were plotted on the cross-sectional MRI data of the subject. As a result the dipole of the wave V of auditory brainstem responses was found near the contralateral midbrain.

Acoustic Stimulation↗
PubMed1991

[Preliminary screening for antiviral AIDS drugs. II. Report on fiscal year 1989].

Preliminary screening for antiviral AIDS drugs was carried out using three different in vitro assay systems. Among 104 samples tested, six were found to inhibit the growth of HIV in vitro. Four of six were acidic polysaccharides of sea weed origin and one was a well-known anti HIV chemical whose anti-HIV activity has not been reported.

Antiviral Agents↗
PubMed1991

[Effect of a proton pump inhibitor AG-1749 (lansoprazole) on intragastric pH: 24-hour intragastric pH monitoring].

Proton pump inhibitors, as agents for use against peptic ulcers, potently suppress gastric acid secretion, as is the case with H2 receptor antagonists. To evaluate this antisecretory action as objectively as possible, intragastric pH was continuously monitored during 24 hours. Eight subjects were enrolled and divided into 2 treatment groups: a group receiving a daily dose of 30 mg of AG-1749 (lansoprazole) and the other group receiving 60 mg. Intragastric pH recording was made in each subject before and after the consecutive administration of the drug, and the corresponding pH holding time was calculated to evaluate the effect obtained in each group. The result indicated that the proportion of time in 24 hours after medication during which the pH was maintained above each level was significantly larger than that after placebo administration, and the duration of action was superior to that of H2-receptor antagonists. From the above, it was concluded that the consecutive administration of ag-1749, at doses of 60 mg as well as 30 mg, exhibits excellent antisecretory action in terms of intragastric pH control.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1991

Detection of PIVKA II produced by human hepatoma cells in nude mice.

A novel experimental nude mouse model, which is useful for investigation of the mechanisms of PIVKA II synthesis, was established by inoculation with PIVKA II-producing human hepatoma cells (huH-1). We have found markedly elevated levels of PIVKA II in the plasma of nude mice transplanted with huH-1 cells and increased PIVKA II content in huH-1 tumor tissues. Whereas we have not found detectable level of PIVKA II neither in the plasma nor in tumor tissues of nude mice transplanted different human hepatoma cells (HLF) which is not producing PIVKA II. Histology of the tumor tissues produced by huH-1 cells revealed a thick trabecular pattern with blood spaces.

Animals↗
PubMed1991

[Molecular heterogeneity of alpha-fetoprotein in ovarian or extragonadal yolk sac tumor].

The molecular heterogeneity of alpha-fetoprotein (AFP) in yolk sac tumor (YST) was investigated. The study included 14 sera from YST, 78 sera from primary hepatocellular carcinoma (PHC), 5 fetal yolk sac (YS) culture fluids and 4 fetal liver culture fluids. The microheterogeneity of AFP was assessed by differences in reaction with AFP carbohydrate chain and lectins, and concanavalin A (Con A), Lens culinaris hemagglutinin (LCH) and phytohemagglutinin E (PHA-E) affinity crossed-line immunoelectrophoresis was used to fractionate AFP. It was found that AFP in YST or YS had similar subfraction patterns and differed clearly from AFP in PHC or fetal liver. Characteristic features of AFP subfraction in YST or YS were the presence of a LCH weakly-reactive subfraction and a high proportion of both Con A non-reactive and PHA-E strongly-reactive subfractions. The LCH weakly-reactive subfraction was specifically found in YST or YS, but was not found at all in PHC or in fetal liver. This variant is known to exist in amniotic fluid at an early stage of gestation, and is assumed to have a carbohydrate chain with both fucose and bisecting N-acetyl-glucosamine. The present findings therefore suggest that glycosylation of AFP in YST takes place by retro-genetic differentiation toward fetal yolk sac, but not toward fetal liver, and these studies confirm the suggested yolk sac origin of ovarian, as well as extragonadal, yolk sac tumor.

Carbohydrate Sequence↗
PubMed1991

[Hematological effect of 14 days treatment of recombinant human granulocyte colony-stimulating factor for neutropenia in myelodysplastic syndromes].

Nineteen patients with myelodysplastic syndromes (MDS) were treated with a glycosylated recombinant granulocyte colony-stimulating factor (rG-CSF) for improvement of neutropenia. rG-CSF was administrated intravenously at a dose of 5 micrograms/kg/day for 14 consecutive days. Most of patients responded to rG-CSF and an approximately 10 fold increase of the peak neutrophil counts was observed. The neutrophil counts were maintained at high level during the treatment period and returned to pretreatment levels several days after stopping rG-CSF. Consistent with the recovery of neutrophil, infectious complications improved in many cases. Effects of rG-CSF were confined to neutrophils, sparing blast cells and other blood cells. Eruption was observed in one patient as toxicity. We conclude that rG-CSF therapy is effective in improving neutropenia with MDS patients.

Adult↗