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Biomedical subjects

Y Asano

Publications and source records attributed to Y Asano.

At least 613 records · Page 34Linked to original sources
PubMed1988

Identification of human herpesvirus-6 as a causal agent for exanthem subitum.

A virus was isolated from the peripheral blood lymphocytes of patients with exanthem subitum, cultured successfully in cord blood lymphocytes, and shown to be antigenically related to human herpesvirus-6 (HHV-6). Morphological features, as studied by thin-section electronmicroscopy, resembled those of herpes group viruses. Convalescent-phase serum samples, tested against the new viral antigen and HHV-6 antigen, showed seroconversion. The results strongly suggest that the newly isolated virus is identical or closely related to HHV-6 and the causal agent for exanthem subitum.

Acute Disease↗
PubMed1988

Cloning and nucleotide sequencing of phenylalanine dehydrogenase gene of Bacillus sphaericus.

The gene coding for phenylalanine dehydrogenase [PDH; L-phenylalanine: NAD+ oxidoreductase (deaminating); EC 1.4.1.-] from Bacillus sphaericus SCRC-79a was cloned onto plasmid pUC9, and the nucleotide sequence of the 2-kb DNA region of the insert was determined. A 1143-bp open reading frame consisting of 381 codons was identified as a pdh gene coding for PDH.

Amino Acid Oxidoreductases↗
PubMed1988

Analysis of two distinct B cell activation pathways mediated by a monoclonal T helper cell. II. T helper cell secretion of interleukin 4 selectively inhibits antigen-specific B cell activation by cognate, but not noncognate, interactions with T cells.

A single monoclonal T helper (Th) clone can activate B cells in two distinct pathways; a cognate pathway requiring a major histocompatibility complex (MHC)-restricted T-B cell interaction, and a noncognate pathway not requiring an MHC-restricted T-B cell interaction. The present study was undertaken to investigate whether Th cells mediating a given immune response provide further regulatory function to B cells other than helper function. It was demonstrated that conditions of high antigen concentration which activate a noncognate B cell activation pathway simultaneously inhibit IgG responses. The inhibition is shown to be mediated by the T cell factor interleukin 4, produced by activated cloned Th cells. The inhibitory effect of this factor is directed to B cells and is MHC-unrestricted, antigen-nonspecific, and IgG class-specific. In addition to being susceptible to the effects of augmenting cells and suppressor cells, cloned Th cell populations can therefore themselves function as regulatory cells to inhibit IgG responses when stimulated with high dose of specific antigen. These results indicate that Th cells function to regulate B cells both positively and negatively, depending upon the activation conditions.

Animals↗
PubMed1988

Epitopes associated with major histocompatibility complex (MHC) restriction site of T cells. IV. I-J epitopes on MHC-restricted cloned T cells.

We studied the expression of an I-Jk epitope on class II-restricted cloned L3T4+ T cells established from H-2k, H-2b, F1 and semiallogeneic radiation bone marrow chimeras by the inhibition of antigen-induced T cell proliferation and in vitro secondary antibody response, and by the direct immunofluorescence with a monoclonal anti-I-Jk. Both I-Ak- and I-Ek-restricted T cells were shown to carry the identical I-Jk epitope regardless of their genotypic origins, antigen specificity, and helper or suppressor function. None of the I-Ab-restricted clones derived from similar animals showed the I-Jk epitope. This isomorphism, regardless of the restriction specificity for I-Ak or I-Ek, contradicts the idea that I-J is an idiotypic determinant on class II-restricted T cell antigen receptor (TcR). In fact, the I-Jk epitope was not comodulated with TcR/T3 complex when incubated with an anti-T3 antibody, indicating that I-J is a new isomorphic receptor for self different from TcR alpha/beta heterodimers.

Animals↗
PubMed1988

Placental transfer of IgG subclass-specific antibodies to varicella-zoster virus.

Commercially available mouse monoclonal antibodies to human IgG subclasses (IgG 1 to IgG 4) were used in an enzyme-linked immunosorbent assay to examine the placental transfer of IgG subclass-specific antibodies to varicella-zoster virus (VZV). All 46 mothers had total IgG antibody to VZV, and an equal level of antibody was found in the cord blood. All of the mothers had high antibody activities to VZV in IgG 1 and IgG 4 subclasses. The majority of the mothers were negative for IgG 2 and IgG 3 VZV antibodies, and the level of antibody found to be positive was very low. The IgG 1 antibody activity in the cord blood was almost equal to that of the maternal, and significantly higher level of IgG 4 antibody was found in the cord than maternal blood.

Adult↗
PubMed1988

Further experience with one-stage repair of severe hypospadias and scrotal transposition. Modifications in the technique and its result in eight cases.

Further experience with one-stage repair of severe hypospadias and scrotal transposition performed in eight patients is reported. Primary success was obtained in six, while one patient was cured by secondary repair. While describing the operative technique with some modifications it was reassured that our parameatal preputial flap is a well vascularized one which can safely and easily be constructed into a neourethra. Advantages of improved "glanulomeatoplasty" and scrotoplasty are also discussed. The method is recommended as highly successful to attain excellent functional and cosmetic results in one stage for severe hypospadias.

Child↗
PubMed1988

Effect of human G-CSF on clonogenic cells in acute myeloblastic leukemia.

The effects of purified human native granulocyte colony-stimulating factor (G-CSF) on the growth of clonogenic leukemic blast cells from 10 Japanese patients with acute myeloblastic leukemia (AML) were studied, using an in vitro leukemic blast colony assay. The clonogenic leukemic blast cells from six patients with AML were stimulated to form colonies in viscous medium in vitro by the addition of 100 ng/ml G-CSF. The possibility that G-CSF may be a leukemic blast growth factor warrants further attention.

Adult↗
PubMed1988

One-stage total repair of severe hypospadias with scrotal transposition: experience in 18 cases.

This is a report detailing further experience with our one-stage repair of severe hypospadias and scrotal transposition performed on 18 patients. Initial success was obtained in 12 cases, while two more were improved by secondary repair. The operative technique, as modified, assures a parameatal preputial flap, which is well vascularized and easily constructed into a neourethra. The advantages of this improved "glanulomeatoplasty" and scrotoplasty are discussed. The method is recommended as an excellent functional and cosmetic procedure for one-stage correction of severe hypospadias.

Child, Preschool↗
PubMed1988

Establishment of monoclonal antibody to human androgen receptor and its clinical application for prostatic cancers.

Hybrid cell lines were prepared by the fusion of BALB/c myeloma NS-1 cells with the lymphocytes of BALB/c mice that were immunized with partially purified androgen receptor (AR) from human prostates. One of the clones, 5F4, was chosen for detailed specificity analysis. The avidin-biotin-peroxidase complex (ABC) procedure was used for immunohistochemical staining of the 5F4 monoclonal antibody. In human benign prostatic hypertrophy (BPH) tissues, cytoplasm and nuclei were stained. Of 16 prostatic cancer tissues, 2 were composed of AR-positive cells exclusively, 7 were composed of AR-negative cells, and 7 contained both AR-positive cells and AR-negative cells (mixed). Of nine cases that were AR-positive or mixed, seven cases responded to the hormone therapy, and two were not determined for responsiveness because the patients died early of other diseases. Of seven AR-negative cases, all but one inestimable case had no response to the hormone therapy. Immunohistochemical analysis of AR by using the monoclonal antibody 5F4, was a useful tool for determining androgen dependency of prostatic cancers.

Animals↗
PubMed1988

Computer simulations of nuclear reactions induced by incident protons in the energy range of 100 to 500 MeV in a human body.

Computer simulations of nuclear reactions induced by protons in a human body were carried out in the incident energy range from 100 to 500 MeV. Nuclear reactions by secondary particles produced at primary interactions are included. Nuclides produced by the secondary particles increase smoothly with increasing incident proton energy and they are about 15 and 45% of those produced by the primary protons at 150 and 500 MeV, respectively. The yield of product nuclides by the primary protons is approximately constant in the proton energy range above 150 MeV but drops sharply below 150 MeV.

Computer Simulation↗
PubMed1988

Purification and properties of formate dehydrogenase from Moraxella sp. strain C-1.

NAD+-dependent formate dehydrogenase was screened in various bacterial strains. Facultative methanol-utilizing bacteria isolated from soil samples, acclimated to a medium containing methanol and formate at pH 9.5, were classified as members of the genus Moraxella. From a crude extract of Moraxella sp. strain C-1, formate dehydrogenase was purified to homogeneity, as judged by disc gel electrophoresis. The enzyme has an isoelectric point of 3.9 and a molecular weight of approximately 98,000. The enzyme is composed of two identical subunits with molecular weights of about 48,000. The apparent Km values for sodium formate and NAD+ were calculated to be 13 mM and 0.068 mM, respectively.

Aldehyde Oxidoreductases↗
PubMed1988

Hypochlorhydria and hypergastrinemia and their association with gastrointestinal bleeding in young patients with chronic renal failure.

In 40 young patients with chronic renal failure (CRF) on maintenance hemodialysis and 22 control subjects, (1) basal and test meal-stimulated gastrin concentrations, (2) basal and pentagastrin-stimulated gastric acid outputs, and (3) endoscopic examinations were studied. Age-matched CRF patients with control subjects had higher circulating gastrin levels both in the fasting and the test meal-stimulated state and they also had hypochlorhydria. After a test meal, the peak increment of serum gastrin in the CRF patients was more prolonged and greater than in controls. Endoscopic findings showed that the most predominant lesion in the CRF patients was hemorrhagic gastritis. Nine (64.2%) out of 14 patients were hyposecretors and none were hypersecretors. Patients with hyposecretion had higher gastrin levels as well as the same incidence of abnormal endoscopic findings as patients with normosecretion. It is concluded that hypergastrinemia in young CRF patients might be due to a combined effect of impaired renal clearance capacity and overproduction of gastrin associated with hypochlorhydria and also that the cause of gastritis in the young CRF patients might partly be due to a relative impairment of the mucosal defensive mechanism to acid. Our data suggest that the parietal cell response to gastrin in CRF patient may be impaired.

Adult↗
PubMed1988

Hypochlorhydria and hypergastrinemia and their association with gastrointestinal bleeding in undialyzed and hemodialyzed patients.

In 15 undialyzed (UD) patients and 26 hemodialyzed (HD) patients, (1) basal and test meal-stimulated gastrin concentrations, (2) basal and pentagastrin-stimulated gastric acid outputs, and (3) endoscopic examinations were studied. Also studied were the morphological and functional differences of the gastrointestinal tract between UD and HD patients. HD patients had lower gastric acid outputs and higher circulating gastrin levels in the fasting state. After a test meal, the peak increment of serum gastrin in UD and HD patients occurred 30 and 60 min later, respectively, and the response was prolonged in each group. Endoscopic findings showed that the incidence of abnormalities in each group was very similar, that is, the most predominant lesions in each group were hemorrhagic and atrophic gastritis. The data suggested that the response to gastrin of parietal cell and the defensive mechanism of gastrointestinal mucosa in HD patients may be impaired.

Adult↗