Search PubMed⌕ Search

Biomedical subjects

Y Ueda

Publications and source records attributed to Y Ueda.

At least 631 records · Page 35Linked to original sources
PubMed1993

Pharmacokinetic properties of recombinant feline interferon and its stimulatory effect on 2',5'-oligoadenylate synthetase activity in the cat.

The pharmacokinetic behavior of recombinant feline interferon produced in silkworm infected with recombinant baculovirus harboring cDNA coding for feline interferon was studied in vivo in cats. The decreasing profile of the serum interferon level after intravenous administration was fitted to a two-compartment model. The half-times of the first phase (distribution phase) and second phase (metabolic phase) were 5.0 +/- 0.5 min and 31 +/- 5 min, respectively. In the whole body autoradiogram, at 15 min after the administration, the highest radioactivity was observed in urine in the bladder, and predominant radioactivity in the kidneys, liver, thyroid gland and spleen. Almost no radioactivity was detected in the brain or fat. Three hr after administration, the highest radioactivity was recorded in the thyroid gland, urine in the bladder, intestinal contents, and gastric mucous membrane. The data obtained in this study suggest that recombinant feline interferon has similar pharmacokinetic properties to human interferons and that it is distributed primarily in the liver and kidneys, is catabolized rapidly mainly in the kidneys, and is excreted in the urine without residual accumulation in the body. It was confirmed that 2',5'-oligoadenylate synthetase activity was increased by the interferon in vivo for 3 days after an intravenous bolus injection in cats.

2',5'-Oligoadenylate Synthetase↗
PubMed1993

Homogeneous production of feline interferon in silkworm by replacing single amino acid code in signal peptide region in recombinant baculovirus and characterization of the product.

In a previous paper we reported that we constructed a recombinant baculovirus named BmFeIFN1 which produced recombinant feline interferon (FeIFN) in silkworm after infection. High purification of FeIFN in body fluid from the larvae revealed that two kinds of FeIFN were produced by the BmFeIFN1. The difference between the two in the NH2-terminal amino acid sequence was clarified, and two kinds of processing at different sites in FeIFN precursor were suggested. Changing one residue of the amino acid sequence in deduced signal peptide by site directed mutagenesis of encoding cDNA led to the production of homogeneous FeIFN whose NH2-terminal three amino acid sequence was identical to the conserved sequence of human interferon-alpha. We designated the FeIFN produced as rFeIFN. Amino acid sequence analysis revealed that rFeIFN consisted of 170 amino acid residues. The COOH-terminal amino acid of the rFeIFN is Glu which is located at one amino acid residue upstream to the COOH-terminal amino acid deduced from the nucleotide sequence. Positive periodic acid Schiff reaction, undetectability of Asn at position 79 by automated protein sequencer, and detectability of N-acetylglucosamine not N-acetylgalactosamine suggested that rFeIFN was N-glycosylated. rFeIFN was stable at pH 1.5 at 4 degrees C for at least 50 days, and had an antiviral action on feline calicivirus or feline herpesvirus in vitro. Its isoelectric point was pI 6.5. Comparing the structure and biosynthesis of rFeIFN with those of HuIFNs, rFeIFN may be classified as omega-type.

Amino Acid Sequence↗
PubMed1993

Enhanced proliferative potential in culture of cells from p53-deficient mice.

Normal somatic cells are endowed with limited doubling potential in culture, and the process of immortalization is an inevitable step in neoplastic transformation of the cells. To examine the roles of p53 in this process, the cells of p53-deficient mice were examined for doubling potential. Fibroblast-like cells from a variety of tissues of these mice proliferated continuously without showing aging or crisis. The aneuploid cells overcome the population with passage, but cloning experiment indicated that chromosomal changes were not essential to this process. The enhanced proliferative potential in culture of cells from the p53-deficient mice was also observed in epithelial cells of lens, mammary glands and seminal vesicles and in neural precursor cells. Proliferation of bone marrow cells in response to stem cell factor was enhanced in long term culture, but not in in vitro colony assay; no permanent cell lines could be obtained. No effects of p53-deficiency were found in proliferation of cardiac muscle cells or hepatocytes.

Aneuploidy↗
PubMed1993

[Treatment of hemolytic uremic syndrome].

Since the pathogenesis of hemolytic uremic syndrome (HUS) has not been fully understood, it is difficult to establish a therapy protocol for HUS. Until now, there have been no effective treatments of HUS, evaluated by prospective controlled studies. Progress in the management of acute renal failure has improved the prognosis of HUS. Recently, the effectiveness of plasma infusion has been considered to be doubtful. Antiplatelet therapy and vitamin E administration may be recommended to treat typical HUS without severe complications. In addition to these treatments, plasma exchange using fresh plasma or fresh frozen plasma is recommended to treat HUS in the adult, atypical HUS and typical HUS with severe complications in childhood, considering the poor prognosis in these conditions.

Adult↗
PubMed1993

[General anesthesia conducted twice in myotonic dystrophy].

A 42-year-old woman with myotonic dystrophy underwent general anesthesia twice. In the first operation, muscle rigidity was recognized when the patient was placed on lithotomy position under anesthesia with thiopental and nitrous oxide. In the second operation, rigidity was not observed under vecuronium, sevoflurane-nitrous oxide anesthesia. Neuromuscular monitoring of this patient did not show any difference of neuromuscular blockade with vecuronium compared with other 9 normal patients. We conclude that vecuronium and sevoflurane can be used safely in a patient with myotonic dystrophy under neuromuscular monitoring.

Adult↗
PubMed1993

Analysis of secretory leukocyte protease inhibitor (SLPI) in bronchial secretions from patients with hypersecretory respiratory diseases.

Changes in the content and molecular state of secretory leukocyte protease inhibitor (SLPI) in the airways in chronic airway diseases were studied. SLPI in bronchoalveolar and bronchial lavage fluids (BALF and BLF) from normal subjects and patients with diffuse panbronchiolitis (DPB), and in mucoid sputa from patients with emphysema and in purulent sputa from DPB patients were examined by ELISA and Western blotting. Results showed that in the BALF and BLF of normal subjects, the SLPI/alpha 1-protease inhibitor (alpha 1-PI) ratios (M/M) are about 0.6 and 6, respectively and the neutrophil elastase inhibitory capacity of BLF is mainly due to SLPI. In the BALF and BLF of DPB patients, both the elastase activity and alpha 1-PI level are increased, but the SLPI level is decreased. In purulent sputa, the elastase activity was found to be 430-fold that in mucoid sputa and the alpha 1-PI level to be 3.5-fold that in mucoid sputa, but the SLPI level was slightly lower in the mucoid sputa. Analysis by Western blotting showed that in BLF from normal subjects and mucoid sputa, SLPI is present in an intact form and in complexes with other substances, whereas in BLF and purulent sputa from DPB patients, SLPI is present in a degraded form and in complexes with other substances, but not in the intact form. These results indicate that SLPI is the main protease inhibitor in the airways of both normal subjects and patients with hypersecretory respiratory diseases without infection, but that its level is insufficient to overcome the increased protease burden in the airways of DPB patients.

Adult↗
PubMed1993

Voltage-operated calcium channels in fresh and cultured rat retinal pigment epithelial cells.

PURPOSE: There is little known about the membrane properties of retinal pigment epithelial (RPE) cells with respect to calcium. The authors attempted to characterize membrane calcium channels from solitary fresh and cultured RPE cells from normal and dystrophic rat retinas. METHODS: RPE cells were enzymatically dissociated from eyes of neonatal rats of several strains, including dystrophic RCS strains. Membrane currents were recorded using the whole-cell version of the patch-clamp technique from either fresh or cultured cells. RESULTS: The authors observed sustained high-voltage-activated calcium channels that were dihydropyridine sensitive and closely resembled neuronal L-type calcium channels. The RCS-rdy+p+ strain was mainly investigated, but high-voltage-activated calcium channels were also recorded from fresh RPE cells of other rats regardless of age or strain, including RCS p+, RCS rdy+, Long Evans, Sprague Dawley, and also cultured RPE cells taken from a neonatal Long Evans strain. Low-voltage-activated calcium channels were not observed in any of these cells. CONCLUSION: Voltage-operated calcium channels of the L-type are the main calcium channels present in rat RPE cells. Cultured cells retained the identical channels. The dystrophic RCS strains (studied until 17 days postnatal) also exhibited these channels.

Animals↗
PubMed1993

Spectroscopic characterization of heterochiral DNAs.

We have synthesized heterochiral dodecadeoxynucleotides having an unnatural L-nucleotide residue, and have investigated their structures by ultraviolet (UV) absorption, circular dichroism (CD) measurements and nuclear magnetic resonance (NMR) spectroscopy. It was clearly shown that the overall structures of the heterochiral 12-mers are a right-handed B-conformation and the unnatural L-nucleotide residue in the heterochiral 12-mer (L-4) forms stable Watson-Crick type base-pairing with the natural complementary residue. In this double helix (L-4), the unnatural G4 residue has an S-type sugar conformer and a low-anti glycosidic torsion angle. From the properties of an enantiomer, natural nucleotides may possibly form a low-anti left-handed B-form duplex with the aid of certain factors.

Base Sequence↗
PubMed1993

Comparative evaluation of left ventricular performance after mitral valve repair or valve replacement with or without chordal preservation.

The clinical importance of preserving the chordae tendineae during mitral valve replacement was assessed by comparing the postoperative left ventricular performances in 68 patients who underwent mitral valve replacement (MVR) with complete chordal preservation (n = 19), conventional MVR (n = 25) or mitral valve repair (n = 24) and had full hemodynamic assessment before and after surgery. The pre- and postoperative left ventricular performances were analyzed using cineangiography, multiple-gated cardiac blood pool scintigraphy (MUGA), and echocardiography. In the early postoperative period, cineangiography revealed that the end-systolic volume index (ESVI) and the end-diastolic pressure were significantly higher in the conventional MVR group. The left ventricular ejection fraction was unchanged in the chordal preservation group, but was decreased in the mitral repair and conventional MVR groups. The end-systolic circumferential left ventricular wall stress (ESS) was significantly decreased in the chordal preservation and mitral repair groups, but was unchanged, and thus higher, in the conventional MVR group. The postoperative left ventricular contractility index (ESS/ESVI) was better in the chordal preservation than in the conventional MVR group. In the late postoperative period, both the left ventricular ejection fraction as measured by MUGA and the left ventricular fractional shortening as measured by echocardiography were significantly higher in the mitral repair and chordal preservation groups than in the conventional MVR group. This study supports the concept that the maintenance of continuity between the mitral annulus and the papillary muscles has a beneficial effect on postoperative left ventricular performance.

Adult↗
PubMed1993

[A clinicopathological study of a patient with paraneoplastic limbic encephalitis, myelitis, sensory neuropathy and cerebellar degeneration, associated with a unique antineuronal antibody].

Clinicopathological and immunohistochemical studies were performed in a patient with paraneoplastic limbic encephalitis, myelitis, sensory neuropathy and cerebellar degeneration secondary to small cell lung cancer. A 67-year-old male smoker developed orthostatic dizziness 6 months prior to admission. Over the following months, his wife noticed that he became forgetful and confused. Over the next three weeks, he became unable to sit or stand unaided and admitted to our service. On admission, he was lethargic and disoriented in time and place. Neurological examination revealed marked limb weakness with distal dominant muscle atrophy. A chest radiograph demonstrated a mass in the right middle lobe and a bronchial biopsy revealed a small cell carcinoma. CT scan and MRI of the brain revealed abnormalities in the bilateral medial temporal lobes and putamen. He was treated with anti-cancer chemotherapy, but died of respiratory failure after 13 months illness. Postmortem examination showed a mass in the right middle lobe of the lung. No tumor metastases were noted in the nervous tissue. Microscopical examinations of the nervous system revealed neuronal loss, astrogliosis and perivascular and parenchymatous lymphocytic infiltration in the hippocampus, subiculum, amygdala, putamen, medulla oblongata, spinal cord and dorsal root ganglia. Loss of Purkinje cells was also seen in the cerebellum without lymphocytic infiltration. Immunohistochemical analysis of the patient's serum and CSF by the use of adult rat brain revealed immunoreactivity at the hippocampal pyramidal neurons CA3 and CA4. At the higher dilution, neuronal nuclei were specifically stained.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

[The protective effect of continuous retrograde cerebral perfusion on the central nervous system during deep hypothermic systemic circulatory arrest].

Deep hypothermic circulatory arrest (DHCA) was introduced as an adjunct for operations involving aortic arch lesions in 1970's and has since been widely used. Profound hypothermia protects the brain and other vital organs by reducing metabolic rate. We initiated the use of continuous retrograde cerebral perfusion (CRCP) via the superior vena cava during DHCA in 1987. We studied 15 patients who required DHCA and CRCP during repair or replacement of the aortic arch. CRCP times ranged from 11 to 78 (mean +/- S.D.; 37.3 +/- 21) minutes, and minimal nasopharyngeal temperatures ranged from 13.7 to 25 (17.7 +/- 2.6) degrees C. Two patients died one month postoperatively due to preoperative disease. Three patients, who were in shock preoperatively due to cardiac tamponade, developed acute renal failure postoperatively. The remaining patients were weaned from the respirator by the 2nd postoperative day. No patient had CRCP-related complications. During CRCP, the partial pressure of oxygen (PO2), saturation of oxygen (SO2), and oxygen content significantly decreased (p < 0.001), and the partial pressure of carbon dioxide (PCO2) and CO2 content significantly increased (p < 0.001) between retrogradely perfused blood and blood draining from the arch vessels. These results most probably reflected that the aerobic metabolism of the brain was maintained by CRCP while the central nervous system was maintained in a hypothermic state, with oxygen and substrate availability, wash-out of metabolites, and buffering capacity and oncotic pressure of the blood maintained. This technique offers the potentials of sufficient metabolic support to the brain during DHCA and prolonged safe time limits of DHCA.

Adult↗
PubMed1992

The effects of a unique D-loop structure of a minor tRNA(UUALeu) from Streptomyces on its structural stability and amino acid accepting activity.

Streptomyces bldA gene, which encodes a tRNA corresponding to a very minor leucine codon, UUA, regulates pleiotropic gene expression which is involved in sporulation and secondary metabolism. The unique structural feature of this tRNA is the lack of GG sequence in dihydrouridine loop (D-loop) that generally is conserved in tRNAs involved in cytoplasmic protein biosynthesis. In order to investigate the relationship between the D-loop structure and the stability and leucine accepting activity of this tRNA, the wild and D-loop mutant tRNA transcripts were constructed with T7 RNA polymerase in vitro. The wild type tRNA(UUALeu) showed the structural stability and leucine accepting activity at physiological temperature for Streptomyces. The E.coli type D-loop mutant, which has a larger loop size and contains a GG doublet, exhibited increased thermostability. The kinetical analyses of the aminoacylation reaction of tRNA(UUALeu) with S.lividans and E.coli leucyl-tRNA synthetase (LeuRS) suggest there is a unique recognition mechanism of Streptomyces LeuRS toward tRNA(UUALeu).

Base Sequence↗
PubMed1992

Synthesis and properties of mirror-image DNA.

We have investigated the conformations of the hexadeoxyribonucleotide, L-d(CGCGCG) composed of L-deoxyribose, the mirror image molecule of natural D-deoxyribose. In this paper, we report the synthesis of four L-deoxynucleosides and the L-oligonucleotide-ethidium bromide interactions. The L-deoxyribose synthon 9 was synthesized from L-arabinose with an over all yield of 28.5% via the Barton-McCombie reaction. The L-deoxynucleosides were obtained by a glycosylation of appropriate nucleobase derivatives with the 1-chloro sugar 9. After derivatization to nucleoside phosphoramidites, L-deoxycytidine and L-deoxyguanosine were incorporated into a hexadeoxynucleotide, L-d(CGCGCG) by a solid-phase beta-cyanoethylphosphoramidite method. This L-hexanucleotide was resistant to digestion with nuclease P1. The conformations of L-d(CGCGCG) were an exact mirror image of that of the corresponding natural one as described previously, and the conformations of the L-d(CGCGCG)-ethidium bromide complex were also the mirror images of those of the D-d(CGCGCG)-ethidium bromide complex under both low and high salt conditions. These results suggest that ethidium bromide prefers not a right-handed helical sense, but the base-base stacking geometry of the B-form rather than that of the Z-form. Thus, L-DNA would be a useful tool for studying DNA-drug interactions.

Chromatography, High Pressure Liquid↗
PubMed1992

In vivo calcium elevations in thymocytes with T cell receptors that are specific for self ligands.

Selection of the T cell receptor (TCR) repertoire in the thymus probably involves TCR-mediated signals transduced in developing thymocytes after interaction with thymic stromal cells bearing self ligands. TCR-transduced signals should have identifiable consequences that would distinguish thymocytes whose TCRs have been engaged by self ligands from those whose TCRs have not. Among thymocytes expressing a transgenic TCR of defined specificity, a large number had elevated intracellular calcium concentrations but only when resident in a negatively selecting thymus in which their self ligand was expressed. Thus, developing thymocytes are stimulated by endogenous ligands in vivo to mobilize intracellular calcium, and increased intracellular calcium concentrations may reflect the consequences of intrathymic signaling associated with thymic negative selection.

Animals↗