Biomedical subjects

Y Tani

Publications and source records attributed to Y Tani.

At least 145 records · Page 8Linked to original sources

PubMed1995

[An autopsy of an HIV infected patient with dilated cardiomyopathy (DCM)].

A case of a HIV infected 61-year-old bisexual male with dilated cardiomyopathy (DCM) is reported. The death was originally recorded as from undetermined causes, but on autopsy, his heart showed left ventricular dilatation macroscopically, variety in size and vacuolation of cardiomyocyte, partial deciduation of cardiac muscle and diffuse perivascular fibrosis microscopically. These findings were compatible with DCM which was compounded by excessive weight loss. The further data indicated that the etiology of DCM in this case was directly related to the HIV infection.

Cardiomyopathy, Dilated↗

PubMed1995

[Evaluation of immunochromatography assay technique for detection of antibody to hepatitis B surface antigen (HBsAg)].

A new immunochromatography assay (Dainascreen Ausab Dainabot) has been recently introduced for the detection of the presence of antibody to HBsAg. To evaluate the feasibility of using the Dainascreen Ausab, we carried out comparison tests with this method and PHA. In the test of 439 sera from HB vaccinees, inhabitants in Iki Island, Nagasaki Pref., patients with autoimmune diseases and with acute hepatitis B, 154 (31.2%) were positive by Dainascreen Ausab, 145 (29.4%) were positive by PHA and 145 (29.4%) were positive by both Dainascreen Ausab and PHA. Nine (1.8%) were positive by only Dainascreen and there were none positive by only PHA. A good correlation was observed between the titer of the antibody by this method and IMx. The anti-HBs assay by this method was able to be completed within 15 minutes and the procedure was very simple. The results indicate that the sensitivity of Dainascreen is superior to PHA and that it is easy to use.

Chromatography, Thin Layer↗

PubMed1995

Distribution and properties of fructosyl amino acid oxidase in fungi.

Fructosyl amino acid oxidase, and enzyme that can be used for the determination of glycated proteins in blood samples from diabetic patients, was used to screen cultures in our microorganism culture collection. Fructosyl amino acid oxidase was found only in the strains of four genera of fungi, Aspergillus, Fusarium, Gibberella, and Penicillium and exhibited different substrate specificities against fructosyl valine and N epsilon-fructosyl N alpha-Z-lysine. A fructosyl valine-specific enzyme from Penicillium janthinellum AKU3413 was monomeric (M(r), 49,000), was most active at 35 degrees C and pH 8.0, and had a covalently bound flavin adenine dinucleotide as a prosthetic group.

Amino Acid Oxidoreductases↗

PubMed1995

Development of electroretinographic alterations in streptozotocin-induced diabetes in rats.

Development of electroretinographic alterations in 9-week-old experimental diabetic rats was studied for up to 6 weeks after a single intraperitoneal injection of streptozotocin (STZ, 60 mg/kg). The amplitudes and the peak latencies of the a and b waves in the diabetic rats did not differ significantly from those in the control rats. In contrast, the diabetic rats showed a significantly smaller amplitude of the second oscillatory potential (OP) 6 weeks after STZ treatment, and furthermore significantly delayed OP peaks as early as 2-3 weeks after STZ treatment. Vitreous fluorophotometric abnormality developed 6 weeks after STZ treatment. None of the diabetic rats had fundus angiographic changes. These results suggest that hyperglycemia or its related changes rapidly affects the light-induced electrical activities of the retina.

Animals↗

PubMed1995

[Hemodynamic and neurohumoral effects of carperitide (alpha-human atrial natriuretic peptide) in dogs with low-output heart failure].

We examined the hemodynamic and neurohumoral effects of carperitide in dogs with low-output heart failure (LHF) produced by volume expansion, ligation of the left anterior descending coronary artery and methoxamine infusion. Carperitide (0.1 approximately 1 micrograms/kg/min, i.v. infusion for 30 min) decreased pulmonary arterial pressure, right atrial pressure and systemic vascular resistance and increased cardiac output. These pharmacological activities were equivalent to those of nitroglycerin (NG, 3 micrograms/kg/min). Although most of the animals did not excrete urine after induction of LHF, carperitide, unlike NG, increased urine volume. The plasma level of cyclic GMP was elevated about three times by induction of LHF and further increased after treatment with carperitide (1 microgram/kg/min). Carperitide had no effects on plasma renin activity, plasma aldosterone concentration and plasma noradrenaline. These results taken together indicate that carperitide reduces both preload and afterload in association with an increase in cyclic GMP production and improves the untoward hemodynamic alterations in LHF dogs.

Acute Disease↗

PubMed1995

Purification and properties of fructosyl lysine oxidase from Fusarium oxysporum S-1F4.

Fructosyl lysine oxidase (FLOD) was examined for its use in the enzymatic measurement of the level of glycated albumin in blood serum. To isolate microorganisms having such an enzyme activity, we used N epsilon-fructosyl N alpha-Z-lysine (epsilon-FL) as a sole nitrogen source in the enrichment culture medium. The isolated fungus, strain S-1F4, showed a high FLOD activity in the cell-free extract and was identified as Fusarium oxysporum. FLOD was purified to an apparent homogeneity on SDS-PAGE. The molecular mass of the subunit was 50 kDa on SDS-PAGE and seemed to exist in a monomeric form. The enzyme had an absorption spectrum characteristic of a flavoprotein and the flavin was found to be covalently bound to the enzyme. The enzyme acted against N epsilon-fructosyl N alpha-Z-lysine and N alpha-fructosyl N epsilon-Z-lysine and showed specificity for fructosyl lysine residues.

Amino Acid Oxidoreductases↗

PubMed1995

Dentin surface treatment without acids.

Enhancement of the adhesiveness of dental restoratives, such as composite resins, has been clinically essential. A key point in enhancing adhesion is how to treat the dentin surface before bonding. We recently attempted to use an inorganic and non-acidic salt solution for pretreatment to dentin. We paid attention to the salting-in effect of rhodanides which promotes swelling of collagen and gelatin. For pretreatment, we used potassium thiocyanate (KSCN) solution. This study morphologically evaluated the effect of treatment of dentinal smear layer with rhodanides in combination with cross-linking agents such as ferric chloride. Scanning electron microscopy revealed effective removal of the smear layer on the treated dentin surface and obturation of dentinal plugs. Addition of the cross-linking agents to KSCN solution was more effective for pretreatment.

Alum Compounds↗

PubMed1995

[Fine needle aspiration cytology in screening of prostatic cancer].

Between October 1990 and June 1993, 112 patients underwent fine needle aspiration cytology and core needle biopsy of the prostate under transrectal ultrasonographic guidance. They were suspected of having prostatic cancer from the prostatic antigen level, digital rectal examination and/or transrectal ultrasonography. Twenty seven of the 112 cases (24%) were diagnosed with prostatic cancer. Their cytological diagnoses showed 22 class IV or V, 2 class III, and 3 class I or II. Efficiency, false negative rate and false positive rate were 86%, 11% and 0% in fine needle aspiration cytology. We could obtain sufficient samples for fine needle aspiration cytology in all cases. No severe complication was observed. However, we missed 3 patients, in fine needle aspiration cytology, who were strongly suspected of having prostatic cancer, and reexamination or additional core needle biopsy would have been necessary on 15 of the 112 patients (13%) who showed false negative or class III cytological results, if we had screened prostatic cancer only by fine needle aspiration cytology. In conclusion, fine needle aspiration cytology may not be as useful as core needle biopsy to screen prostatic cancer.

Adenocarcinoma↗

PubMed1995

[Analysis of relationship between personality and emesis gravidarum in pregnant women].

The relationship between personality types and the symptoms of emesis gravidarum in pregnant women was analyzed by means of the Cattel personality test (revised by Nishizono) performed in early and mid pregnancy. Personality types were classified into five from cyclothymia A to schizothymia E. As for emesis, the patients were also classified into three groups, severe (35), mild (41) and none (19), according to the severity and duration of the symptoms. As a result, there was no significant difference between the types and the symptoms, but significant differences were seen in interpersonal attitudes, especially in sociality and dominative propensity, which were constituents of the personality type. The results of the analysis suggested that the patients who revealed disunification tended to express strong emesis as a somatic language. These results therefore indicate the necessity for counseling about personality without simply explaining it as their predisposing constitution, when we encounter strongly emetic pregnant women.

Female↗

PubMed1994

Decrease in 6R-5,6,7,8-tetrahydrobiopterin content in cerebrospinal fluid of autistic patients.

The levels of pterin compounds in the lumbar cerebrospinal fluid (CSF) of ten neurologically normal and twenty autistic children were measured by two different liquid chromatographic systems, a conventional and a newly developed direct method. Among pterin compounds 7,8-dihydroneopterin (NH2) and 6R-5,6,7,8-tetrahydrobiopterin (R-BH4) levels in autistic children were significantly reduced to 66.1 and 41.5%, respectively, of those found in the controls. The autistic children were divided into three subgroups according to their CSF homovanillic acid (HVA) level and age: the group with an elevated HVA level, the younger (< 7 year old) group with a normal HVA level, and the older (> 7 year old) group with a normal HVA level. In comparison, the further reduction was observed in NH2 and R-BH4 levels in the younger group and in the 7,8-dihydropterin (PH2) level in the group with an elevated HVA level. Thus, these results suggest that the endogenous biosynthesis of R-BH4 in the brain may be reduced in autistic children as compared with that in neurologically normal children.

Adolescent↗

PubMed1994

Oncostatin M, leukemia inhibitory factor, and interleukin 6 induce the proliferation of human plasmacytoma cells via the common signal transducer, gp130.

We analyzed the stimulatory effect of oncostatin M (OSM), leukemia inhibitory factor (LIF), interleukin 6 (IL-6), IL-11, and the inhibitory effect of anti-IL-6 antibody (Ab), anti-IL-6 receptor monoclonal antibody (mAb), and anti-gp130 mAb on the growth of human plasmacytoma cells freshly isolated from a patient with multiple myeloma. The purified cells showed a plasmacytoid morphology and expressed CD38, CD54, and CD56 antigens but no CD3, CD5, CD10, CD19, CD20, or very late antigen 5. IL-6 receptor (IL-6R) and its signal transducer, gp130, were expressed on their cell surface at a low level. Dose-dependent proliferation of the cells in response to OSM, LIF, and IL-6, but not to IL-11, was observed using [3H]TdR incorporation in vitro. Both anti-IL-6 Ab and anti-IL-6R mAb inhibited the growth of the cells in the presence or absence of exogenous IL-6. These cells release IL-6 but not OSM or LIF into the culture supernatant during short-term culture. Therefore, an autocrine growth mechanism mediated by IL-6, but not by OSM or LIF, was confirmed. Furthermore, anti-gp130 mAb completely inhibited the proliferation of the cells induced by OSM, LIF, as well as IL-6. These data indicate that OSM, LIF, and IL-6 can act as growth factors of human plasmacytoma cells through a common signal transducer, gp130, on their cell surface, and also suggest the potential therapeutic application of anti-gp130 mAb, as well as anti-IL-6R mAb against myeloma/plasmacytomas.

Antibodies, Monoclonal↗

PubMed1994

Effect of 6R-L-erythro-5,6,7,8-tetrahydrobiopterin on in vivo L-[beta-11C]dopa turnover in the rat striatum with infusion of L-tyrosine.

L-[11C]DOPA, combined with positron emission tomography (PET), has made possible the assessment of dopamine turnover in vivo. Before the evaluation of PET study with L-[11C]DOPA in the primate, the effect of 6R-L-erythro-5,6,7,8-tetrahydrobiopterin (6R-BH4) and/or L-tyrosine infusion on L-[11C]DOPA turnover was analyzed in the rat striatal tissue and in the striatal extracellular fluid using microdialysis. L-[11C]DOPA was rapidly taken up into the brain after intravenous injection and converted to [11C]dopamine, [11C]DOPAC and [11C]HVA in the striatal tissue. Small amount of 3-O-methyl-[11C]DOPA, a product of DOPA by 3-O-methylation in peripheral tissues, was also detected in the striatal tissue. The striatum/cerebellum ratio of total radioactivity uptake was linear against time up to 40 min after L-[11C]DOPA injection. The uptake ratio, increased by 6R-BH4 administration, was further increased by L-tyrosine infusion. The in vivo microdialysis technique was further applied to determine L-[11C]DOPA and its metabolites in striatal extracellular fluid (ECF). The peripheral administration of 6R-BH4 (50 mg/kg) induced elevation of [11C]DOPA concentration in ECF in the early phase after injection, following higher radioactivity in [11C]dopamine and [11C]HVA fractions than those in control animals at late phase. The 6R-BH4-induced elevation of [11C]DOPA uptake and the radioactivity of its metabolites was further enhanced by the continuous infusion of L-tyrosine at a dose of 1.0 mumol/min/kg. L-Tyrosine infusion alone did not induce the elevation of radioactivity. The results suggest that [11C]DOPA might be a useful probe to evaluate the effect of 6R-BH4 and/or L-tyrosine loading in the primate.

Animals↗

PubMed1994

Inverse correlation between the titre of antibody to hepatitis C virus and the degree of hepatitis C viraemia.

We titrated 277 hepatitis C virus (HCV) antibody-positive serum samples from 235 volunteer blood donors as well as from 42 outpatients of a hospital for elderly people and studied the relation of the titre of HCV antibody to the presence of HCV RNA, of antibody to C100 protein (anti-c100) and of antibody to GOR epitope (anti-GOR). Liver dysfunction was measured also. Of 177 HCV RNA-positive serum samples, 87 were tested for the degree of HCV viraemia by means of a competitive assay. Among the 277 samples, prevalences of HCV RNA, anti-c100, anti-GOR and liver dysfunction were 63.9%, 71.8%, 75.7% and 17.5%, respectively. The prevalence of HCV RNA became higher as the titre of HCV antibody increased. The titre tended to increase with age but the tendency was not statistically significant. The mean titre was higher in females (2(10.4 +/- 1.8)) than in males (2(9.4 +/- 2.2)) (P < 0.01). In the HCV RNA-positive serum samples, the HCV antibody titre was significantly higher in the anti-c100-positive samples than in the negative ones. This difference between the positive and negative samples, however, was not statistically significant for anti-GOR and liver dysfunction. Low degrees of HCV viraemia were accompanied by high titres of HCV antibody while high degrees of HCV viraemia went with low titres of HCV antibody. The study revealed that titres of HCV antibody were higher in females and the degree of HCV viraemia correlated inversely with the titre of HCV antibody.

Adolescent↗

PubMed1994

High-level ATP production by a genetically-engineered Candida yeast.

Previous studies of ATP production with the methylotrophic yeast, Candida boidinii, suggested that the phosphorylation of AMP catalyzed by adenylate kinase (ADK) was rate-limiting. To investigate whether the enhancement of ADK activity in C. boidinii cells would improve ATP productivity, the Saccharomyces cerevisiae ADK1 gene encoding ADK was expressed in C. boidinii under the C. boidinii AOD1 promoter. Methanol-induced transformants had 10,000-fold enhanced levels of ADK activity and produced 23-fold more ATP from adenosine when compared to the control, parent strain. In a pH-controlled reaction system with successive adenosine-feeding, the ATP concentration in the reaction mixture reached 230 mM (117 g/l) over 45 hours, and was easily purified with an overall yield of 78 percent.

Adenosine Kinase↗

PubMed1994

Inhibitory effects of caffeine on secretagogue-induced catecholamine secretion from adrenal chromaffin cells of the guinea-pig.

1. The inhibitory action of caffeine on catecholamine secretion induced by secretagogues was investigated in perfused adrenal glands and dispersed chromaffin cells of the guinea-pig. 2. Caffeine (10 mM) caused a reversible inhibition of catecholamine secretion evoked by acetylcholine (ACh, 50 microM), KCl (56 mM, high K+) and veratridine (100 microM) and that induced by muscarinic receptor activation in the absence of extracellular Ca2+ in perfused adrenal glands. 3. In dispersed chromaffin cells, caffeine caused a dose-dependent inhibition of the secretory responses to 100 microM ACh and veratridine. Forskolin (30 microM), dibutyryl cyclic AMP (1 mM) and 8-bromo cyclic AMP (1 mM) did not mimic the action of caffeine. 4. In the voltage-clamp, whole-cell recording mode (at a holding potential of -60 mV or -70 mV), ACh (100 microM) evoked an inward current, and depolarizing pulses elicited inward Na+, Ca2+ and outward K+ currents. All these responses were partially inhibited by caffeine (20 mM). 5. ACh rapidly increased the intracellular concentration of Ca2+ ([Ca2+]i) in fura-2-loaded cells in either the presence or the absence of external Ca2+, though its magnitude was decreased by about 50% in Ca(2+)-free conditions. Caffeine (20 mM) inhibited these ACh-induced increases in [Ca2+]i. 6. In permeabilized chromaffin cells, caffeine (20 mM) caused an inhibition of catecholamine secretion evoked by Ca2+ (10 microM). 7. These results suggest that caffeine inhibits evoked catecholamine secretion through mechanisms such as the blockade of voltage-dependent Na+ and Ca2+ currents and ACh receptor current, and reduction of the release of intracellularly stored Ca2+ and/or Ca(2+)-sensitivity of the secretory apparatus.

8-Bromo Cyclic Adenosine Monophosphate↗

PubMed1994

Enhanced in vitro human immunodeficiency virus type 1 replication in B cells expressing surface antibody to the TM Env protein.

The human immunodeficiency virus type 1 (HIV-1) external envelope glycoprotein gp120 tightly binds CD4 as its principal cellular receptor, explaining the tropism of HIV-1 for CD4+ cells. Nevertheless, reports documenting HIV infection or HIV binding in cells lacking CD4 surface expression have raised the possibility that cellular receptors in addition to CD4 may interact with HIV envelope. Moreover, the lymphocyte adhesion molecule LFA-1 appears to play an important role in augmenting HIV-1 viral spread and cytopathicity in vitro, although the mechanism of this function is still not completely defined. In the course of characterizing a human anti-HIV gp41 monoclonal antibody, we transfected a CD4-negative, LFA-1-negative B-cell line to express an anti-gp41 immunoglobulin receptor (surface immunoglobulin [sIg]/gp41). Despite acquiring the ability to bind HIV envelope, such transfected B cells could not be infected by HIV-1. These cells were not intrinsically defective for supporting HIV-1 infection, because when directed to produce surface CD4 by using retroviral constructs, they acquired the ability to replicate HIV-1. Interestingly, transfected cells expressing both surface CD4 and sIg/gp41 receptors replicated HIV much better than cells expressing only CD4. The enhancement resided specifically in sIg/gp41, because isotype-specific, anti-IgG1 antibodies directed against sIg/gp41 blocked the enhancement. These data directly establish the ability of a cell surface anti-gp41 receptor to enhance HIV-1 replication.

Amino Acid Sequence↗

PubMed1994

Molecular cloning of the rat thyroxine-binding globulin gene and analysis of its promoter activity.

We cloned the rat T4-binding globulin (rTBG) gene, characterized its organization, and studied its promoter activity and regulation. A genomic DNA library was constructed and screened using an rTBG complementary DNA (cDNA) as a probe. An 8.6-kilobase pair (kbp) clone was partially sequenced and compared with the sequence of the previously cloned cDNA. It helped complete the cDNA sequence and identify the first noncoding exon (exon 0). The transcription start site was identified using an RNase protection assay. The rTBG genomic clone contained 1.2 kbp 5'-flanking and 1.7 kbp 3'-flanking regions. The sizes of exons and introns of the rTBG gene are similar to those of the human TBG gene, belonging to the serine protease inhibitor family. The 5'-flanking region contains a TATA box, a CAAT box, and a consensus sequence for the hepatocyte nuclear factor 1-binding site. We tested the promoter activity of the 1.2-kbp 5'-flanking region using a luciferase reporter plasmid. When transfected into a hepatocyte-derived cell line (HepG2), the plasmid construct containing the fragment -1227 to +11 (transcription start site, +1) showed a 9-fold increase in luciferase activity compared with that of a promoterless luciferase vector. No promoter activity was detected in a nonhepatocyte-derived cell line (COS1). Serial 5'-deletion revealed that the construct containing the fragment -180 to +11 had 40% of the maximal promoter-induced luciferase activity. And that containing the fragment -53 to +11 showed no significant increase of luciferase activity. These results suggest that the region -180 to -53, containing hepatocyte nuclear factor 1-binding site, is essential to the liver-specific expression. We previously reported down-regulation of rTBG messenger RNA by T3 in vivo. The present study failed to show T3's effect on the promoter activity of the 1.2-kbp 5'-flanking region of the rTBG gene.

Animals↗

PubMed1994

A truncated thyroxine-binding globulin due to a frameshift mutation is retained within the rough endoplasmic reticulum: a possible mechanism of complete thyroxine-binding globulin deficiency in Japanese.

We have previously reported six unrelated Japanese families having the same mutation in the TBG gene and manifesting complete TBG deficiency (TBG-CDJ). The deficiency consists of a single nucleotide deletion resulting in the production of C-terminal truncation due to a frameshift and premature termination. However, the reason for the failure to detect TBG in the serum of subjects harboring this mutation remains unknown. In this communication we investigated the mechanism of the TBG deficiency associated with TBG-CDJ. The complementary DNAs of TBG-CDJ and normal TBG (TBG-N) were expressed in COS-1 cells. Pulse-chase experiments revealed a complete absence of secretion of TBG-CDJ, whereas TBG-N was already present in the medium at time 0 and was almost entirely secreted by 3 h. In cell lysates, TBG-CDJ had a smaller molecular mass [52 kilodalton (kDa)] than TBG-N (54 kDa) and gradually decreased during the chase. Thus, failure of TBG-CDJ secretion accounts for the complete TBG deficiency. The molecular mass of TBG-CDJ (42 kDa) was also smaller than that of TBG-N (44 kDa) when synthesized in the presence of tunicamycin. These findings are consistent with the premature termination of the TBG-CDJ molecule deduced from the nucleotide sequence analysis. Intracellular TBG-N was resistant to endoglycosidase H but not TBG-CDJ, suggesting the retention of TBG-CDJ within the rough endoplasmic reticulum. Indeed, subcellular fractionation revealed that most of TBG-CDJ was located in the rough endoplasmic reticulum compartment, and TBG-N was distributed in the Golgi fractions. Our results suggested that the lack of intracellular transport of the truncated TBG molecule is the cause for the absence of immunoreactive TBG in the serum of subjects harboring the TBG-CDJ variant.

Animals↗