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Biomedical subjects

K Yasui

Publications and source records attributed to K Yasui.

At least 325 records · Page 18Linked to original sources
PubMed1985

Effect of estrogen (17 beta-estradiol) on the susceptibility of mice to disseminated gonococcal infection.

Studies of the effect of sex hormones on the susceptibility of mice to the disseminated gonococcal infection demonstrated significantly enhanced susceptibility of mice injected with estrogen (17 beta-estradiol). In mice treated with estradiol, bacteremia progressively developed within 12 h postinoculation and mice died within the next 6 h, whereas bacteremia in mice treated with progesterone was completely cleared within 3 h postinoculation. The administration of estradiol affected the function of polymorphonuclear leukocytes (PMN) responsible for eliminating gonococci, but the administration of progesterone did not. The bactericidal activity of PMN mediated by myeloperoxidase was affected by estradiol, but the capacity of PMN to release superoxide anion was not. Furthermore, peritoneal cell analysis demonstrated that the infiltration of PMN in the peritoneal cavity of estradiol-treated mice significantly decreased when mice were injected intraperitoneally with gonococci. These effects on PMN by estradiol may play an important role in the enhanced susceptibility of estradiol-treated mice to gonococcal infection.

Animals↗
PubMed1985

Left ventricular aneurysm and the prediction of left ventricular enlargement studied by two-dimensional echocardiography: quantitative assessment of aneurysm size in relation to clinical course.

A retrospective study was performed to elucidate the process of left ventricular aneurysm formation and its influence on left ventricular enlargement based on serial two-dimensional echocardiographic observations from 150 consecutive patients with first acute anterior myocardial infarction. Echocardiograms were available and interpretable through the entire period of observation in 68 patients. Because of early death in 13 patients, echocardiograms of 55 patients, 22 with and 33 without aneurysm, were analyzed from 1 to 28 days after infarction. Patients with aneurysms were separated into two groups with large (group 1, 11 patients) and small aneurysms (group 2, 11 patients) on the basis of ratios of aneurysm to overall left ventricular circumferential length [Lcf-LV(RAO)] and area [Area-LV(RAO)], i.e., Lcf(An/LV)-RAO and Area(An/LV)-RAO, respectively, in the right anterior oblique equivalent view at the time of aneurysm formation, with reference to Forrester's subset. Group 1 consisted of patients with Lcf(An/LV)-RAO of 0.4 or greater or Area(An/LV)RAO of 0.3 or greater while group 2 included patients with Lcf(An/LV)-RAO less than 0.4 or Area(An/LV)-RAO less than 0.3. In the test for time trend in these groups with a one-way analysis of variance, Lcf-LV in RAO equivalent and apical four-chamber views and Area-LV in apical four-chamber view effectively separated group 1 from groups 2 and 3 (without aneurysm) with significance (p less than .005, p less than .01, and p less than .01).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiomegaly↗
PubMed1985

Induction of undifferentiated brain tumors in rats by a human polyomavirus (JC virus).

Newborn SD rats were inoculated intracranially with JC virus (Tokyo-1), a human polyomavirus, isolated from the autopsied brain of a patient with progressive multifocal leukoencephalopathy. Twenty-one to 61 weeks later, 20 of 27 rats developed tumors in the cerebrum, but not in the cerebellum. The undifferentiated neuroectodermal nature of the tumors was histologically, immunohistochemically and ultrastructurally confirmed.

Animals↗
PubMed1985

[Reversible asynergy in acute transmural myocardial infarction: evaluations of patients with inferior infarction].

To evaluate the significance of chronological changes in wall motion abnormalities, echocardiography was performed for 46 patients with acute transmural inferior myocardial infarction without previous infarction or complications. Asynergy was analyzed by two-dimensional echocardiography (2-D Echo) on the third day (acute stage) and the 28th day (convalescent stage) after the onset of infarction. Asynergy was quantitatively estimated by dividing the left ventricle into 17 segments. The degree of asynergy was graded on a four-point scale as dyskinesis = 3, akinesis = 2, hypokinesis = 1, and normokinesis = 0. The total wall motion score (TWMS) was calculated on the both days. Improvement of asynergy was observed in 39 cases (84.8%). Among them, both the extent and degree of asynergy were improved in 17 cases (37.0%). In 10 cases (21.7%) the extent of asynergy was reduced. In the remaining 12 cases (26.1%), only the degree of asynergy was decreased. Concerning the relationship between the degree of asynergy on the 3rd day and the subsequent alteration of asynergy on the 28th day, two of four dyskinetic segments still had dyskinesis, and the other two reverted to akinesis. Among 156 akinetic segments, 80 did not change, but 58 reverted to hypokinesis and 18, to normokinesis. Among 82 hypokinetic segments, 48 did not change, but 34 became normal. The relationship between severity of asynergy on the third day indicated by the total wall motion score (TWMS 3rd) and the improvement in the score on the 28th day (TWMS 28th) was investigated in three patient groups: group-A (n = 19) showed TWMS 3rd greater than 9; group-B (n = 22), 9 greater than or equal to TWMS 3rd greater than or equal to 3; group-C (n = 5), TWMS 3rd less than 3. The frequency of "no improvement" was slightly higher in the group-C (62.5%) than in the group-A (52.1%) and in the group-B (56.4%). On comparison, improvement of asynergy was observed in the group-A in 47.9% and in the group-B in 43.6%, but the rate of resolution of asynergy was higher in group-B (53.6%) than in the group-A (40.3%). In the group-C, there was no case of significant coronary artery stenosis greater than 75% in diameter and sigma CPK was smaller than in the other two groups (p less than 0.005).(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1985

[Evaluation of myocardial perfusion by intravenous contrast echomyocardiography].

For the echocardiographic assessment of intramyocardial blood flow distribution by intravenous contrast echocardiographic technique, we measured the echo intensity of a point (phi 6 mm) in the interventricular septum using a lightmeter in end-diastole before and after the intravenous injection of various dosages of ether or hydrogen peroxide in one open-chest and four closed-chest dogs. Before the injection of contrast media, the echo intensity of the myocardium varied within a range of 6.1 +/- 4.6% After the injection of ether or hydrogen peroxide, the echo intensity of the myocardium increased. After the occlusion of the left anterior descending artery, echo enhancement of the left ventricular wall occurred, except for the left ventricular anterior wall and the interventricular septum. Between dosage (x) and % increase (y), relations of y = 127x - 3, in ether and y = 1.17x + 1.11, in hydrogen peroxide were observed. We found that the intravenous injection of at least 0.2 ml ether or 15 mg hydrogen peroxide was necessary to achieve effective echo enhancement of the myocardium in dogs.

Animals↗
PubMed1985

Interactions of 2-methyladenines and poly(m2A) with poly(br5U).

Mixing curve experiments and melting curve analyses have shown that poly(m2A) forms complexes with poly(br5U) with stoichiometries of either 1:1 or 1:2 in high ionic strengths. CD spectra of poly(m2A).poly(br5U) and poly(m2A).2 poly(br5U) both resemble quite well to those of poly(A). poly(br5U) and poly(A).2poly(br5U), respectively. This suggests that the corresponding complexes are closely related in the structural details. Significant similarities of the CD spectra were observed for poly(m2A).2poly(br5U) and complexes between 2,9-dimethyladenine or 2-methyladenosine and poly(br5U) in the presence of spermine, indicating also the 1:2 stoichiometry. Thus, a methyl group at the position 2 of adenine ring is not necessarily hindering a formation of the Watson-Crick type base pairings.

Adenine↗
PubMed1984

A monocyte disorder in siblings with chronic candidiasis. A combined abnormality of monocyte mobility and phagocytosis-killing ability.

Immunologic studies were performed on siblings (a 9-year-old boy and an 11-year-old girl) with chronic candidiasis since infancy and showed defective monocyte functions. In vivo migration and in vitro mobility of the monocytes were impaired. In addition, they had defective phagocytosis-killing ability against Candida albicans. There was no factor(s) to inhibit the monocyte functions in the patients' serum, and their mononuclear cells (75% to 80% lymphocytes) did not secrete such an inhibitory factor(s) in vitro. The serum IgG, IgA, IgM, and C3 levels were normal. Delayed hypersensitivity responses to five antigens, including Candida antigen, were absent in the two patients. In vitro T-lymphocyte functions, such as Candida antigen- or mitogen-induced blastogenesis and lymphokine (leukocyte migration inhibitory factor and leukocyte-derived chemotactic factor) production, were normal. The clinical features of our patients were similar to those with chronic mucocutaneous candidiasis (CMC); however, their primary immunologic defect was, unlike that of CMC, in monocytes, but not in T lymphocytes. These results demonstrated a monocyte disorder with defective mobility and phagocytosis-killing ability that contributed to chronic candidiasis.

Blood Bactericidal Activity↗
PubMed1984

Evaluation of left ventricular performance during sympathetic nervous storm in a case with severe tetanus by transesophageal M-mode echocardiography.

Transesophageal M-mode echocardiography was applied for the evaluation of left ventricular performance in a case of severe tetanus with labile hypertension due to sympathetic nervous 'storm'. When systemic blood pressure was elevated, increases in pulmonary arterial pressure, cardiac output, left ventricular enddiastolic diameter, fractional shortening and mean velocity of circumferential fiber shortening were noted. No changes were found in total peripheral vascular resistance or left ventricular endsystolic diameter. Positive pressure ventilation, rendered standard transthoracic echocardiography ineffective.

Blood Pressure↗
PubMed1984

Immunogenic dialyzable factor derived from a ribosomal fraction of Salmonella typhimurium III. Analysis of resistance induced by dialyzable factors.

Dialyzable factors (DF) were prepared from ribosomal fractions of several organisms including rough mutants of Salmonella typhimurium LT2, salmonella species of different serogroups, other enteric bacteria and gram-positive organisms, and tested for their immunogenicity against S. typhimurium infection in mice. All of them conferred local resistance on mice challenged intramuscularly with S. typhimurium LT2 in the early stage of immunization before the establishment of delayed-type hypersensitivity (DTH) to salmonella antigens. Although DFs of enteric bacteria including rough mutants of S. typhimurium induced DTH to salmonella antigens, only DF of a two-heptose mutant of S. typhimurium LT2 afforded significant mouse protection but others only prolonged the mean time to death. DF of Listeria monocytogenes induced the cross-reacting immunity which afforded the low level of mouse protection as well as an increase in mean time to death without inducing DTH. Passive transfer of anti-O antibody did not enhance the mouse protection provided by each DF. Resistance conferred by DF of S. typhimurium LT2 consisted of two phases: (i) nonspecific macrophage activation resulting in reduction of organisms at the infected site, which became active in the early stage of immunization and (ii) salmonella-specific immunity capable of preventing systemic infection, which became active in the late stage of immunization.

Animals↗
PubMed1984

Effect of adjuvants on the rectal absorption and lymphatic uptake of pepleomycin in rats.

The rectal absorption of pepleomycin sulfate (PEPS) in rats was increased significantly by the coadministration with each of diclofenac (DC), sodium 5-methoxysalicylate (5-MSA) and phenylalanine enamine of ethylacetoacetate (Enamine). 5-MSA increased the lymphatic uptake of PEPS after rectal administration while DC and Enamine did not. The mechanism behind the enhancing action of 5-MSA on the lymphatic uptake of PEPS may be due to the suppressing action of 5-MSA on the vascular permeability to PEPS. DC increased the vascular permeability to PEPS but Enamine did not affect it. Findings obtained in this study may indicate that adjuvant used acts independently at the rectal mucosal membrane and at the vascular membrane for membrane for membrane permeability to PEPS.

Adjuvants, Pharmaceutic↗
PubMed1984

Induction of brain tumors by a newly isolated JC virus (Tokyo-1 strain).

A newly isolated virus from a patient with progressive multifocal leukoencephalopathy (PML) (Tokyo-1 strain) was found serologically identical to JC virus (Mad-1 strain) and showed high neurooncogenicity in hamsters. Twenty-one animals inoculated intracerebrally with the virus developed brain tumors during a period that averaged 5 months. The tumors were cerebellar medulloblastoma (n = 20); plexus tumor (n = 2) occurred in 1 animal as a single tumor and in another in combination with a medulloblastoma. Thalamic gliomatosis was also present in 6 animals with medulloblastoma. Five mock-infected animals did not develop tumors. Medulloblastoma cells were shown to contain papovavirus T-antigen. In 20 animals examined the medulloblastoma showed a close resemblance to the human medulloblastoma in its histologic, immunocytochemical, and ultrastructural features. Examination of the incipient tumors indicated that the hamster medulloblastoma originated in cells in the neonatal external granular layer. Following infection the cells apparently migrated into the internal granular layer, carrying integrated virus genes and expressing phenotypical transformation. These findings confirm previous reports on the oncogenicity of virus isolates from PML (ZuRhein and Varakis, 1979), but are novel in that with this new isolate tumors could be induced with comparatively low levels of virus inocula.

Animals↗
PubMed1983

Effects of total pancreatectomy on the secretion of gut glucagon in humans.

To determine how total pancreatectomy influences the secretion of gut glucagon in man, 15 totally pancreatectomized patients (Px), 14 distally gastrectomized patients (Gx), and 15 healthy subjects were investigated by intravenous arginine infusion test and oral glucose tolerance test. Blood glucose, plasma insulin (IRI), and C-peptide (CPR) levels were determined. Plasma immunoreactive glucagon (IRG) and total glucagon-like immunoreactivity (total GLI) were also measured. Gut glucagon-like immunoreactivity (gut GLI) was calculated to be the difference between total GLI and IRG. In the Px group, arginine infusion did not significantly alter the levels of IRI, CPR, IRG, and gut GLI. Mean basal value of gut GLI in the Px group of 356 +/- 40 pg/ml was significantly higher than 179 +/- 26 pg/ml of the healthy (p less than 0.01) and 182 +/- 24 pg/ml of Gx group (p less than 0.01). Oral glucose loading led to the highest increase of gut GLI in the Px group (p less than 0.01). Thus, extrapancreatic IRG may not be secreted into the plasma in totally pancreatectomized humans in response to arginine stimulation. Complete absence of the pancreas and the deficiency of insulin-effect may lead to a hypersecretion of gut GLI, both in the basal state and after oral glucose loading.

Adult↗
PubMed1983

Topographical analysis of antigenic determinants on envelope glycoprotein V3 (E) of Japanese encephalitis virus, using monoclonal antibodies.

Ten monoclonal antibodies directed against envelope glycoprotein V3 (E) of Japanese encephalitis virus were obtained. They were characterized by hemagglutination inhibition (HI), neutralization, and enzyme-linked immunosorbent assay and divided into four types: flavivirus-cross-reactive HI and non-neutralizing antibody (group 1), subgroup-specific HI and non-neutralizing antibody (group 2), low HI and neutralizing antibody (group 3), and non-HI and neutralizing antibody (groups 4 and 5, respectively). Competitive binding assays were performed to analyze the topography of antigenic determinants by enzyme-linked immunosorbent assay. The results of the competitive binding assay separated non-HI and neutralizing antibody into groups 4 and 5, respectively, and demonstrated the existence of at least five distinct antigenic determinants on V3. The site of group 1 was distinct from any other site. The sites of groups 2 and 3 seemed to be located close together. Our results suggest the following relationship between HI and neutralization: (i) The HI sites are separated from the neutralization sites, and (ii) there are two distinct HI sites, one of which is flavivirus cross-reactive, the other subgroup specific.

Antibodies, Monoclonal↗
PubMed1983

[Effect of diltiazem on diastolic performance of the hypertrophied left ventricle in patients with systemic hypertension and hypertrophic cardiomyopathy].

We studied the effect of a calcium antagonist, diltiazem, on left ventricular (LV) diastolic performance of hypertrophied hearts in five patients (pts) with systemic hypertension (HHD) and 6 pts with hypertrophic cardiomyopathy (HCM) by a combined phonoechocardiographic technique. Data were analyzed before and after the oral administration of diltiazem (90-180 mg/day). In HHD, the prolonged LV isovolumic relaxation time, measured from the onset of the aortic component of the second heart sound to the beginning of the mitral valve opening, decreased significantly from 112 +/- 17 to 90 +/- 9 msec (p less than 0.01) and normalized LV peak filling rate during rapid filling phase increased in all pts without a statistic significance. This filling rate during atrial contraction phase decreased (1.61 +/- 0.59 to 0.93 +/- 0.22 sec-1, p less than 0.05). In HCM, LV isovolumic relaxation time and normalized LV peak filling rate during rapid filling phase showed no significant change, although normalized LV peak filling rate during atrial contraction phase decreased significantly (1.20 +/- 0.27 to 1.05 +/- 0.24 sec-1, p less than 0.05). In both pts groups, no significant changes were observed in R-R interval, systolic blood pressure, LV end-systolic dimension, end-diastolic dimension and fractional shortening of the LV minor axis before and after the administration of diltiazem. These data indicate that diltiazem shortens abnormally prolonged LV diastolic relaxation time and improves LV diastolic filling in pts with HHD, whereas diltiazem failes to show such effects in pts with HCM except for a decrease in the normalized LV peak filling rate during atrial contraction phase.

Administration, Oral↗
PubMed1983

Interaction of N6-substituted-9-methyladenines to poly-5-bromouridylic acid.

Interaction of N6-methyl-9-methyladenine (m6m9A) to poly-5-bromouridylic acid (poly(BU] was investigated. The stoichiometry of interaction was determined to be 1 m6A:2 BU by equilibrium dialysis. Structural information was obtained from circular dichroism and absorption spectra and a similarity of the structure to the corresponding polymer complex was suggested. Thermodynamic parameters of the interaction was calculated from dependence of TmS on the monomer concentration and compared to those from calorimetric measurements. N6-(delta 2-Isopentenyl) - and N6-allyl-9-methyladenine were also examined of the binding to poly(BU).

Adenine↗