Biomedical subjects

Y Maeda

Publications and source records attributed to Y Maeda.

At least 631 records · Page 35Linked to original sources

PubMed1992

Effect of phosphoenolpyruvate on metabolic and morphological recovery of red cells after prolonged liquid storage and subsequent freezing in glycerol medium.

The present study was designed to determine the effects of (i) phosphoenolpyruvate (PEP) treatment of red blood cells (RBCs) previously cold stored for a prolonged period in a liquid medium and (ii) the freezing of these treated cells in glycerol. RBCs stored for 21 days at 4 degrees C were incubated for 30 min at 37 degrees C with rejuvenant solution containing 50 mM PEP, 60 mM mannitol, 30 mM sodium chloride, 25 mM glucose, and 1 mM adenine, pH 6.0, and then frozen at -80 degrees C for 4 weeks. Red cell recovery as frozen and thawed red cells (FTRCs) after deglycerolization was increased to 80 +/- 4% compared to 43 +/- 9% in units without rejuvenation; the percentage of PEP-treated FTRCs was similar to the percentage of FTRCs recovered from fresh RBCs within 5 days after donation. Incubation of RBCs with PEP solution restored ATP and 2,3-DPG to levels seen in fresh RBCs, and also facilitated transformation of crenated RBCs to discocytes. These results indicate that maximum recovery of viable RBCs can be attained when FTRCs are processed from cells stored in the frozen state after they had been rejuvenated with PEP even after prolonged liquid storage.

2,3-Diphosphoglycerate↗

PubMed1992

Regional differences in insulin receptor function in Werner's syndrome.

Werner's syndrome is a genetic disease characterized by premature aging and is often associated with glucose intolerance due to insulin resistance. The clinical manifestations in this syndrome are preferentially expressed in the face and acral regions without apparent involvement of the trunk. We compared insulin receptor binding and amino acid uptake of fibroblasts derived from the forearm that had sclerodermoid features, and from the abdomen that was apparently normal in a patient with Werner's syndrome. In normal controls, specific insulin binding was not different in forearm and abdomen-derived fibroblasts (10.72 +/- 2.11%, 10.40 +/- 1.27%, respectively). In the patient, however, specific insulin binding was reduced in the fibroblasts derived from the forearm compared with those derived from the abdomen (3.55%, 8.16%, respectively). Scatchard analysis revealed that the reduction in insulin binding of the forearm fibroblasts from the patient was due to a reduction in receptor number with no change in receptor affinity. The dose-response curve for insulin of alpha-aminoisobutyric acid (AIB) uptake is shifted to the right in the fibroblasts derived from the acral area. The results show that in a patient with Werner's syndrome, regional differences occur in fibroblast insulin receptor binding and function. This suggests early phenotypic expression of the genetic abnormality of insulin receptor function in these patients.

Abdomen↗

PubMed1992

The changes in body temperature, oxygen consumption, CO2 production and muscle protein turnover rate by selection for body size in Japanese quail, Coturnix coturnix japonica.

1. Body temperature, oxygen consumption, CO2 production and muscle protein degradation rate were measured in the three quail lines selected for body size, a random bred line (RR) and two lines selected for large (LL) or small (SS) body size. 2. The body temperature at 15 weeks of age was highest for small body size line and lowest for large body size line. 3. The body temperature, oxygen consumption and CO2 production of females were significantly higher than that of males. 4. The fractional degradation rate of muscle protein of SS, RR and LL lines were measured as 2.4, 1.6 and 1.2% per day in male, and 2.6, 1.7 and 1.4% per day in female.

Animals↗

PubMed1992

Transfusion-associated graft-versus-host disease in a presumably immunocompetent patient after transfusion of stored packed red cells.

A 54-year-old woman developed transfusion-associated graft-versus-host disease (TA-GVHD) after the transfusion of stored packed red cells obtained from unrelated donors. The patient was presumed to be immunocompetent. A diagnosis of TA-GVHD was made by clinical features and postmortem pathologic findings. Sex chromatin analysis of the patient's lymphocytes demonstrated chimerism. HLA typing of the blood donors revealed one to be HLA-homozygous for one of the patient's HLA haplotypes (A33-B44-Cblank). This case illustrates the risk in the general patient population of TA-GVHD after routine blood transfusion therapy. Workers should be aware of this possibility and should continue searching for an efficient way to prevent it.

Blood Component Transfusion↗

PubMed1992

Capillary filling analysis by digital subtraction angiography for vertebro-basilar insufficiency.

Vertebro-basilar insufficiency (VBI) is a vague clinical entity including several symptoms such as faintness, dizziness, vertigo. Millikan and Siekert reported a 'syndrome of intermittent insufficiency of basilar arterial system'. But vascular abnormalities responsible for such symptoms are often hardly diagnosed by conventional angiography, because vertebro-basilar artery systems have many kinds of anomalous congenital origins. Conventional angiography gives us arterial informations such as stenosis, occlusion and malformations, but it often fails to reveal capillary perfusions because of its relatively poor density resolution. Digital subtraction angiography (DSA) is considered to have improved density resolution, and it may enable us to detect vascular perfusions more sensitively in the capillary phase. In this study, we evaluated the usefulness of the capillary filling analysis in digital subtraction angiography for diagnosis of VBI.

Capillaries↗

PubMed1992

Characterization of a mouse/human chimeric monoclonal antibody (C beta 1) to a principal neutralizing domain of the human immunodeficiency virus type 1 envelope protein.

A chimeric mouse-human antibody (C beta 1) was constructed that recognized the principal neutralizing domain (PND) of human immunodeficiency virus type 1 (HIV-1) gp120. The constant (C) immunoglobulin regions (C gamma 1 and C kappa) of a mouse monoclonal antibody, 0.5 beta, were substituted for the human C gamma 1 and C kappa by recombining the DNA modules encoding variable or C regions. The DNA constructs were then transfected into X63 Ag8.653 myeloma cells. A clone with a high production of the chimeric antibody (C beta 1) was selected. This antibody was tested for its biological activity against HIV-1. It bound to the surface of HTLV-IIIB-infected cells and reacted with gp120/160 with equal affinity and specificity to that of the parental 0.5 beta murine monoclonal antibody in a Western blot assay. Neutralization and/or enhancement of HIV infection were evaluated with C beta 1 and 0.5 beta. Both C beta 1 and 0.5 beta neutralized cell-to-cell infection and cell-free virus infection by HTLV-IIIB. Antibody-dependence enhancement of HIV infection was not observed with either C beta 1 or 0.5 beta in the presence or absence of human complement. Antibody-dependent cell-mediated cytolysis (ADCC) and antibody-dependent complement-mediated cytolysis (ACC) were observed with C beta 1 but not with the parental 0.5 beta. These findings suggest that the neutralizing antibodies to PND may neutralize but not enhance HIV infection. Furthermore, the high levels of ACC and ADCC shown against HIV-infected cells by C beta 1 indicate that the clinical application of such monoclonal antibodies may be possible.

Amino Acid Sequence↗

PubMed1992

Changes in the reactivity and neutralizing activity of a type-specific neutralizing monoclonal antibody induced by interaction of soluble CD4 with gp120.

Antibodies directed against the third hypervariable loop-domain (V3 loop) of human immunodeficiency virus type 1 (HIV-1) gp120 inhibit the infection by HIV-1 in a type-specific manner without interfering with the binding of gp120 to CD4. Previous studies demonstrated that soluble CD4 (sCD4) induced the dissociation of gp120 with gp41 and caused conformational changes within the envelope oligomer. We report changes in the binding and neutralizing activity of a monoclonal antibody against the V3 loop after sCD4 binding to gp120. Flow cytometry revealed that a type-specific neutralizing monoclonal antibody against V3 loop of HTLV-IIIB, 0.5 beta, reacted with HTLV-IIIMN-infected cells after exposure to sCD4. When the sCD4-treated HTLV-IIIMN infected cells were analyzed by two-color flow cytometry, most of the CD4-bearing cells were 0.5 beta-positive, indicating that this reactivity of 0.5 beta was associated with the binding of sCD4 to the infected cells. To determine the cross-neutralization by 0.5 beta after exposure to sCD4, HTLV-IIIMN viruses pretreated with sCD4 were used to infect susceptible target cells. The addition of 0.5 beta significantly reduced the p24 antigen production (66.1 +/- 5.9 pg/ml) compared with a control murine IgG (221.3 +/- 15.3 pg/ml). In contrast, no significant reduction in the p24 antigen production was observed by adding the HTLV-IIIMN neutralizing monoclonal antibody, mu 5.5, (209.9 +/- 15.0 pg/ml). Taken together, these results suggest that sCD4/gp120 binding could induce conformational/antigenic changes within the V3 loop that result in the induction of cross-reactivity and cross-neutralizing activity of a type-specific monoclonal antibody.

Antibodies, Monoclonal↗

PubMed1992

Cyclic AMP and Ca2+ as regulators of zygote formation in the cellular slime mold Dictyostelium mucoroides.

To analyze the mechanism of the sexual process (macrocyst formation) in the cellular slime mold Dictyostelium mucoroides-7 (Dm7), the effects of 3',5'-cyclic adenosine monophosphate (cAMP), conditioned medium (CM) factors, and various ions including Ca2+ on zygote formation were examined. The application of cAMP was found to inhibit the sexual cell fusion. In addition, the activity of fusion inhibitor(s) contained in CM was heat stable and lost by phosphodiesterase (PDE)-treatment, thus indicating that cAMP is the inhibitor, being in contrast to ethylene as a fusion activator. Pulse experiments using two cAMP analogues, 2'-deoxy-cAMP and 8-bromo-cAMP suggested that the signal transduction system through the cell surface cAMP receptor is of particular importance for regulation of the sexual fusion process. Among several ions having effects on zygote formation, Ca2+ seemed to be necessary both for the acquisition of fusion competence and for cell fusion itself. In the presence of Ca2+, K+ and Na+ had the opposite effects on zygote formation; K+ was stimulative, while Na+ inhibitory. The significance of these findings is discussed in relation to the regulatory mechanism of zygote formation.

8-Bromo Cyclic Adenosine Monophosphate↗

PubMed1992

A case of tardive Tourette-like syndrome.

We have had experience in treating tardive Tourette-like syndrome on a chronic schizophrenic patient. The patient was a 38-year-old woman. A diagnosis of schizophrenia was made in 1971 and she received repeated medications for 17 years. In 1989, she began to show vocal tic with coprolalia and motor tic. The medications were haloperidol 18 mg, zotepine 200 mg, levomepromazine 100 mg, biperiden 3 mg and nitrazepam 10 mg at the beginning of Tourette-like syndrome. We have tried to change the medications but this tardive Tourette-like syndrome continued to hang on. However, the symptoms gradually improved after a change in drugs; cessation of biperiden 3 mg and the administration of clonazepam 3 mg. The present case suggested that tardive Tourette-like syndrome might be a subtype of neuroleptic-associated tardive syndromes which might be treated with clonazepam.

Adult↗

PubMed1992

FR 113680: a novel tripeptide substance P antagonist with NK1 receptor selectivity.

1. We have discovered a novel tripeptide substance P (SP) antagonist, FR 113680 [N alpha-[N alpha-(N alpha-acetyl-L-threonyl)-N'-formyl-D- tryptophyl]-N-methyl-N-phenylmethyl-L-phenylalaninamide]. In binding experiments, FR 113680 inhibited [3H]-SP binding to guinea-pig lung membranes (NK1) in a competitive manner but had not effect on [3H]-SP binding to rat cerebral cortical membranes (NK1), [3H]-neurokinin A ([3H]-NKA) binding to rat duodenum smooth muscle membranes (NK2) and [3H]-eledoisin (Ele) binding to rat cerebral cortical membranes (NK3). 2. In bioassay experiments, FR 113680 dose-dependently inhibited SP-induced guinea-pig ileum contraction (NK1), but did not inhibit either NKA-induced rat vas deferens contraction (NK2) or neurokinin B (NKB)-induced contraction of rat portal vein (NK3). According to Schild plot analysis, the inhibitory effect of FR 113680 on SP-induced guinea-pig ileum contraction is competitive and the pA2 value is 7.53. 3. The inactivity of FR 113680 on NK1 receptors in rat compared to guinea-pig may represent species-specific forms of the NK1 receptor. 4. These findings suggest that FR 113680 interacts selectively with the NK1 neurokinin receptor.

Animals↗

PubMed1992

Pharmacological profile of a high affinity dipeptide NK1 receptor antagonist, FK888.

1. In our search for compounds that inhibit the binding of [3H]-substance P (SP) to guinea-pig lung membranes, the dipeptide SP antagonist, FK888, was developed by chemical modification of the parent compound, (D-Pro4, D-Trp7,9,10, Phe11)SP4-11. 2. In a [3H]-SP binding assay using guinea-pig lung membranes and rat brain cortical synaptic membranes, FK888 displaced [3H]-SP binding with a Ki value of 0.69 +/- 0.13 nM and 0.45 +/- 0.17 microM, respectively, in a competitive manner. 3. FK888 inhibited the contraction of guinea-pig isolated ileum induced by SP in the presence of atropine and indomethacin (a NK1 receptor bioassay) with a pA2 value of 9.29 (8.60-9.98). 4. FK888 inhibited contractions of rat vas deferens by NKA (a NK2 receptor bioassay) and of rat portal vein by NKB (a NK3 receptor bioassay) at concentrations at least 10,000 times greater than that required to inhibit contractions of guinea-pig ileum. 5. FK888 also inhibited SP-induced airway oedema in guinea-pig after both intravenous and oral administration. 6. These data demonstrate that FK888 is a potent and selective NK1 antagonist which is active both in vitro and in vivo.

Administration, Oral↗

PubMed1992

Linear antigenic regions of the structural proteins of human T-cell lymphotropic virus type I detected by enzyme-linked immunosorbent assays using synthetic peptides as antigens.

We synthesized 46 sequential peptides 21 to 39 amino acids long over the structural protein of human T-cell leukemia virus type I (HTLV-I; the p19 and p24 gag protein and the gp46 and p20E env proteins) and tested their reactivities against antibodies in sera from HTLV-I healthy carriers and patients diagnosed as having human T-cell leukemia-lymphoma (ATLL) and myelopathy (HAM) by using an enzyme-linked immunosorbent assay. Of the 46 synthetic peptides, 18 peptides (2 corresponding to the p19 gag protein, 2 corresponding to the p24 gag protein, 8 corresponding to the gp46 env protein, and 6 corresponding to the p20E env protein) reacted with antibodies in the sera from HTLV-I healthy carriers. In particular, the peptides comprising amino acids 100 to 119 and 119 to 130 of the gag and 175 to 199, 213 to 236, 253 to 282, and 288 to 317 of the env proteins reacted with antibodies in sera from more than 30% of HTLV-I healthy carriers. These peptides also showed high reactivities to the antibodies in the sera from patients with ATLL and HAM. The results indicate that the predominant antigenic regions of the structural protein of HTLV-I were located at the C-terminal end of the p19 gag protein and the C-terminal half of the gp46 env protein, and the corresponding peptides proved to be useful antigens in detecting antibodies in the sera from individuals infected with HTLV-I.

Amino Acid Sequence↗

PubMed1992

Hormone and autacoid regulation of cAMP production in rat IMCD subsegments.

The inner medullary collecting duct (IMCD) of the rat consists of two structurally and functionally distinct segments, i.e., the initial and the terminal IMCD. To identify factors that may regulate the transport function in the IMCD segments, we assessed whether catecholamines, carbachol, prostaglandin E2 (PGE2), bradykinin, glucagon, calcitonin, parathyroid hormone, or epidermal growth factor affects adenosine 3',5'-cyclic monophosphate (cAMP) production in microdissected tubules in the presence and absence of arginine vasopressin (AVP, 0.1 nM). All experiments were performed in the presence of 3-isobutyl-1-methylxanthine, and cAMP was measured by radioimmunoassay. Epinephrine (greater than or equal to 50 nM) and clonidine (greater than or equal to 1 microM) markedly decreased AVP-induced cAMP levels in both IMCD segments. However, phenylephrine did not show an effect. The inhibitory effect of epinephrine was blocked by yohimbine (50 nM) but not by prazosin (50 nM). In isolated perfused terminal IMCDs, epinephrine inhibited AVP-stimulated urea permeability. Isoproterenol (1 microM), in the absence of AVP, caused a significant increase in cAMP level only in the initial IMCD. Propranolol (1 microM) inhibited this isoproterenol effect, but atenolol did not. Dopamine (less than or equal to 1 microM) had no effect on cAMP levels in either IMCD segment. Carbachol, PGE2, and the various peptide hormones had no effect on cAMP levels (+/- AVP) in either IMCD segment. We conclude that an adrenergic beta 2-receptor is present only in the initial IMCD, where its occupation increases cAMP production. We conclude also that an adrenergic alpha 2-receptor is present in both IMCD segments, where its occupation inhibits AVP-induced cAMP production.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

Effect of serotonin on the immunoreactive thyrotropin-releasing hormone concentrations of the rat stomach.

The effects of serotonin and its related compounds on immunoreactive thyrotropin-releasing hormone (ir-TRH) concentrations of the rat stomach wall and gastric juice were studied. Either serotonin, cyproheptadine or GR38032F was injected intraperitoneally, and the rats were decapitated at various times after the injection. ir-TRH concentrations of the stomach wall and gastric juice were measured by radioimmunoassay, and gastric serotonin concentrations were measured by HPLC. ir-TRH concentrations of the stomach wall decreased, and ir-TRH concentrations of gastric juice increased significantly after serotonin injection. On the other hand, both cyproheptadine and GR38032F did not affect ir-TRH concentrations of the stomach. The effects of serotonin on ir-TRH concentrations of the stomach were significantly blocked by the pretreatment of cyproheptadine and GR38032F. The reciprocal changes of gastric ir-TRH and serotonin concentrations were observed without changes in gastric juice pH. These findings suggest that serotonin stimulates ir-TRH release from the stomach wall into gastric juice, and the effects of serotonin on ir-TRH release may be partly mediated via 5-HT2- and 5-HT3-receptors.

Animals↗

PubMed1992

Efficacy of percutaneous transluminal coronary angioplasty in patients with acute myocardial infarction complicated by cardiogenic shock.

Cardiogenic shock still remains a highly lethal complication of acute myocardial infarction (AMI). This study reviews our hospital experience in treating AMI complicated by cardiogenic shock to evaluate whether coronary angioplasty improves survival or not. We have treated 523 AMI patients from 1985 to 1990, and among these, 26 patients with AMI complicated by cardiogenic shock who underwent percutaneous transluminal coronary angioplasty (PTCA) compose the study group. In 16 patients, PTCA was successful (Groups S) and in 10 patients, unsuccessful (Group F). There were no statistical differences between the Groups with respect to clinical background, intraaortic balloon counterpulsation (IABP) or emergency coronary bypass graft surgery. Before PTCA, hemodynamic variables including cardiac index, pulmonary capillary wedge pressure and systolic blood pressure were similar in the 2 groups. After PTCA, cardiac index in Group S patients was better than in Group F patients (2.18 +/- 0.61 versus 1.62 +/- 0.65, p less than 0.05). Thirty day and 1 year survivals were also better in Group S than in Group F (30 day survival: Group S 56.2%, Group F 10%, 1 year survival: Group S 31.2%, Group F 0%, p less than 0.05). Multivariate analysis showed that age under 75 years old, systolic blood pressure over 90 mmHg after PTCA and successful PTCA were independent predictors of 30 day survival (p less than 0.05). It was suggested that PTCA was an effective procedure to reduce mortality in patients with cardiogenic shock.

Adult↗

PubMed1992

A method to eliminate odor from recirculating air in the animal house.

A new method to eliminate odors from air recirculating in an animal house is described. The new system consists of an ozonizer and titania silica ozone decomposition catalyst in the terminal of a recirculating ventilation system. The principle underlying the elimination of odors is the oxidative reaction of malodorous components on the surface of the catalyst caused by coupling with ozonolysis. This method appeared superior in terms of its durability, efficiency and lack of resistance to air flow.

Animals↗

PubMed1992

[Mutagenicity tests of suplatast tosilate (IPD-1151T)].

1. The reverse mutation test was carried out on suplatast tosilate (IPD-1151T) at dose range of 50-5000 micrograms/plate using Salmonella typhimurium strains TA100, TA1535, TA98 TA1538 and TA1537, and Escherichia coli strains WP2, WP2uvrA. In all tester strains no significant differences were observed in the number of revertant colonies as compared with solvent control in the absence or presence of mammalian metabolic activation system. 2. The chromosomal aberration test on IPD-1151T was carried out using cultured Chinese hamster lung cells (CHL). The cells were treated with IPD-1151T at the doses of 125, 250 and 500 micrograms/ml without S9 Mix and at the doses of 1250, 2500 and 5000 micrograms/ml with S9 Mix. The incidence of structural- and numeral-aberration was 0-4% in the absence or presence of mammalian metabolic activation system, no significant increases were observed in the incidence of chromosomal aberrations. 3. The micronucleus test using BDF1 male mice was conducted in order to evaluate the in vivo mutagenicity of IPD-1151T. IPD-1151T was orally administered at doses of 625, 1250, 2500 and 5000 mg/kg, with a sampling time of 24 hr. The frequency of polychromatic erythrocytes with micronuclei (MNPCE) was 0.23% in the lowest dose (625mg/kg) of IPD-1151T, but the frequency of MNPCE was 0.03-0.13% in the groups treated with 1250-5000 mg/kg of IPD-1151T and no significant increases were observed with dose dependence. The results indicated that IPD-1151T was negative, even in the assessment standard using our background data. 4. The present study indicates that IPD-1151T has no in vitro and in vivo mutagenic potential.

Administration, Oral↗

PubMed1992

[Antigenicity tests of suplatast tosilate (IPD-1151T)].

Antigenicity of suplatast tosilate (IPD-1151T) was investigated in guinea pigs and mice. The results were as follows: 1. Homologous passive cutaneous anaphylaxis (PCA), active systemic anaphylaxis (ASA), active cutaneous anaphylaxis (ACA) and Schultz-Dale reaction tests were carried out using guinea pigs which were immunized orally with IPD-1151T alone or subcutaneously with IPD-1151T and Freund's complete adjuvants (CFA). Positive reactions in these tests were not produced by eliciting injection of IPD-1151T or its metabolite, M-1. On the other hand, the sensitization of ovalbumin (OVA) with CFA produced positive reactions in all of PCA, ASA, ACA and Schultz-Dale tests. 2. Heterologous passive cutaneous anaphylaxis (PCA) test using rats was carried out using two strains of mice (C3H/He and BALB/c) which were immunized orally with IPD-1151T alone or intraperitoneally with IPD-1151T and aluminum hydroxide gel (Alum) as an adjuvant. No animals showed positive reaction to both eliciting antigens, IPD-1151T and M-1. On the other hand, a positive reaction in PCA test to eliciting antigen, OVA, was obtained in rats treated with sera of mice sensitized with OVA plus Alum. 3. These findings showed that IPD-1151T had no antigenicity in guinea pigs and mice.

Administration, Oral↗