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Biomedical subjects

T Yasuda

Publications and source records attributed to T Yasuda.

At least 649 records · Page 36Linked to original sources
PubMed1990

Type I familial amyloid polyneuropathy. A pathological study of the peripheral nervous system.

The neuropathological changes were examined in 2 cases of type I familial amyloid polyneuropathy (FAP), confirmed by a genetic study with human transthyretin (prealbumin) cDNA. These cases were from different foci of type I FAP in Japan, but showed a similar pathology in the peripheral nerves. Loss of dorsal root and sympathetic ganglion neurons, predominantly those of small size, was prominent, whereas ventral horn cells were well preserved. Distally accentuated axonal loss with marked axonal sprouting was the principal feature. Fibre sprouts were ubiquitous throughout the nerves and affected the fibre size distribution. Segmental demyelination and remyelination were prominent in the proximal portions of nerves, but axonal degeneration was more conspicuous in the distal portions. The centrally-directed branches of the primary sensory neurons did not show distally-accentuated axonal loss in the dorsal columns. Amyloid deposits were present universally in the endoneurial spaces of the peripheral nerves, but more prominently in the dorsal root ganglia, sympathetic ganglia and more proximal portions of the nerves, and the distribution correlated well with the occurrence of the pathology of peripheral nerves. Neurofilamentous accumulation was frequent in the proximal axons and neuronal cell bodies of the sensory and sympathetic neurons. Schwann cells and satellite cells to which amyloid deposits were attached frequently showed disappearance of basement membrane and proliferation of distorted processes. The findings in the present cases suggest that the Schwann and satellite cells may be directly affected by the amyloid deposits, but the pathogenetic mechanism of marked axonal and neuronal involvement still remains to be elucidated.

Adult↗
PubMed1990

Analysis of the molecular requirements for T cell recognition and activation by using Ia-containing lipid vesicles and stopped-flow fluorometry.

Using Ia antigen-containing lipid vesicles, we investigated by stopped-flow fluorometry the requirements for helper T cell recognition and activation. When azobenzenearsonate-L-tyrosine (ABA-L-Tyr)-specific, I-Ak-restricted helper T cell hybridomas 2-45-12 were mixed with ABA-L-Tyr and purified I-Ak molecules on lipid vesicles, an increase of intercellular calcium ion concentration ([Ca2+]i) in the T cells were detected within 1-2s. The average increases of [Ca2+]i were not much different when the lipid vesicles were composed of dimyristoylphosphatidylcholine or of egg phosphatidylcholine, but they were dependent on the density of I-Ak molecules on the liposomes. The increase of [Ca2+]i was inhibited in the presence of anti-I-Ak monoclonal antibody 10.2.16, but not by the addition of anti-L3T4 monoclonal antibody GK1.5. However, the addition of anti-L3T4 antibody during the first 3 h of cultivation completely inhibited the T cell activation [interleukin (IL-2) production]. In our experimental system, IL-2 production was observed either when L3T4-positive T cell hybridomas 2-45-12 were stimulated with ABA-L-Tyr and Ia molecules on the vesicles in the presence of phorbol 12-myristate 13-acetate, or when L3T4-negative T cell hybridomas 3H60.12 were incubated with ABA-L-Tyr and Ia molecules on the planar membranes.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Human genetically polymorphic deoxyribonuclease: purification, characterization, and multiplicity of urine deoxyribonuclease I.

A deoxyribonuclease I was purified from the urine of a 46-year-old male (a single individual) by using a series of column chromatographies to a homogeneous state as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme was found to be a glycoprotein, containing 1 fucose, 7 galactose, 10 mannose, 6 glucosamine, and 2 sialic acid residues per molecule. The N-terminal amino acid sequence up to the 27th residue of the enzyme was similar to that of pancreatic deoxyribonuclease I from bovine and other species. The catalytic properties of the enzyme derived from a single individual closely resembled those of deoxyribonuclease I purified from human urine collected from several volunteers [Ito, K. et al. (1984) J. Biochem. 95, 1399-1406]. The purified enzyme was found to consist of multiple forms with different pI values. These findings are compatible with the existence of genetic polymorphism of deoxyribonuclease I in human urine previously reported [Kishi, K. et al. (1989) Hum. Genet. 81, 295-297]. This multiplicity of the urine enzyme might be due to variations in the primary structure and/or differences in the content of sialic acid.

Amino Acid Sequence↗
PubMed1990

Inhibitory effect of liposomes containing sulfatide or cholesterol sulfate on syncytium formation induced by bovine immunodeficiency virus-infected cells.

The effect of galactocerebroside 3'-sulfate (sulfatide) or cholesterol sulfate on syncytium formation induced by bovine immunodeficiency virus (BIV)-infected cells was investigated in vitro. Sulfatide was purified from bovine brain and incorporated in liposomes which were composed of egg phosphatidylcholine (PC), cholesterol (Chol), and dipalmitoylphosphatidic acid (DPPA). Either sulfatide- or cholesterol sulfate-containing liposomes effectively prevented syncytium formation induced by BIV-infected cells, but the inhibitory effect of sulfatide alone on syncytium formation was low. On the other hand, neither liposomes containing galactocerebroside nor liposomes composed of egg PC, Chol, and DPPA had any effect on syncytium formation induced by BIV-infected cells. These results suggest that liposomes containing sulfatide or cholesterol sulfate are an efficient agent to inhibit syncytium formation induced by BIV-infected cells, and that sulfate residue might play an important role in the inhibition of syncytium formation.

Animals↗
PubMed1990

Adrenal medulla transplantation into the putamen in Parkinson's disease.

Autologous adrenal medulla was transplanted into the putamen of a patient with severe Parkinson's disease. After the operation, the patient's akinesia and rigidity decreased and the duration of action of L-dopa treatment was prolonged. The effect lasted for only 6 months, however, following which the patient's condition gradually began to deteriorate again, returning to the preoperative state by 12 months after surgery. This paper discusses possible reasons why the effect was only temporary.

Adrenal Medulla↗
PubMed1990

Moisture adsorption-desorption effect on the structure of inclusion complex of 6-chloro-2-pyridylmethyl nitrate and beta-cyclodextrin.

A new anti-anginal drug, 6-chloro-2-pyridylmethyl nitrate (FR46171), was found to form a complex with beta-cyclodextrin (beta-CyD), molecular ratio 1:1. The FR46171/beta-CyD complex thus prepared showed a moisture adsorption-desorption hysteresis characteristic of hydrophilic polymers. The moisture adsorption-desorption isotherm and differential scanning calorimetry indicated that the moisture adsorbed FR46171/beta-CyD complex includes 13-15 mol of water while the moisture desorbed complex includes 5 mol of water. X-ray diffraction patterns of these samples confirmed their different structures. The scanning electron photomicrographs and the surface areas (BET) suggested that the moisture adsorption-desorption hysteresis observed in FR46171/beta-CyD complex can be attributed to reversible hydrogen bonding between water molecules and hydroxyl groups.

Adsorption↗
PubMed1990

[Studies on the sub-MIC of beta-lactam antibiotics--bactericidal activity in compromised host's serum].

Bactericidal activity in compromised host's serum i.e. patients with cancer, the elderly, diabetes, was stronger than that in normal serum against Proteus mirabilis (P. mirabilis) but was weaker against Klebsiella pneumoniae (K. pneumoniae). Against Escherichia coli (E. coli), bactericidal activity on serum of patients with cancer was weaker in the following order, that in elderly serum, that in diabetic serum. Against Proteus vulgaris (P. vulgaris), bactericidal activity in elderly serum was similar to that in normal serum but was stronger than that in serum of patients with cancer. Against Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus), bactericidal activity in elderly serum and diabetic serum was similar to that in normal serum but was weaker than that in serum of patients with cancer. Piperacillin showed bactericidal activity in nutrient broth, normal serum and compromised host's serum at a concentration of 1/4 MIC against E. coli, P. mirabilis and P. aeruginosa. Aspoxicillin showed bactericidal activity in nutrient broth, and bactericidal or bacteriostatic activity in normal serum and serum of patients with cancer against E. coli and P. aeruginosa. While cefazolin and cefmetazole slightly inhibited the growth of bacteria in nutrient broth, they showed hardly any bactericidal activity in normal serum and compromised host's serum.

Aged↗
PubMed1990

Paradoxical activity of beta-lactam antibiotics against Proteus vulgaris in experimental infection in mice.

In previous papers (Y. Ikeda and T. Nishino, Antimicrob. Agents Chemother. 32:1073-1077, 1988; Y. Ikeda, T. Nishino, and T. Tanino, Antimicrob. Agents Chemother. 31:865-869, 1987), we reported that many of the 7-aminothiazolyl cephalosporins, such as cefmenoxime, showed paradoxically reduced activity against Proteus vulgaris at higher concentrations, whereas these paradoxical effects were not observed for other types of cephalosporins, such as cefbuperazone and cefoperazone. In this study, we compare the therapeutic effect of cefmenoxime with that of cefbuperazone and explore the in vivo paradoxical effect of cefmenoxime by using an experimental infection model in mice. In an intraperitoneal infection with P. vulgaris 11, the survival rate with cefmenoxime was increased to 43% at 3.13 mg/kg but was lower at higher doses. On the other hand, cefbuperazone did not show such a paradoxical therapeutic effect. In mice infected with P. vulgaris 11, cefmenoxime levels in both serum and peritoneal washings were rapidly reduced and beta-lactamase activities in the peritoneal cavity were increased at higher cefmenoxime doses. These findings suggested that high levels of cefmenoxime at the infection site induced increased production of beta-lactamase, which then rapidly inactivated the antibiotic. We conclude that the paradoxical therapeutic effect of cefmenoxime against P. vulgaris occurs by the same mechanisms as the in vitro effect and that the high beta-lactamase inducibility and low beta-lactamase stability may account for the paradoxical therapeutic effect of cefmenoxime against P. vulgaris.

Animals↗
PubMed1990

Intracellular activity of tosufloxacin (T-3262) against Salmonella enteritidis and ability to penetrate into tissue culture cells of human origin.

The intracellular antimicrobial activity of tosulfoxacin was tested against Salmonella enteritidis C-32 by using human lung fibroid WI-38 cells and was compared with those of ofloxacin and norfloxacin. The intracellular antimicrobial activities of these drugs were evaluated by determining the numbers of viable organisms remaining within cells after treatment with various drug concentrations. At 0.2 and 0.78 microgram/ml, tosufloxacin suppressed intracellular multiplication of S. enteritidis C-32 more effectively than ofloxacin and norfloxacin did. The ability of tosufloxacin to penetrate into WI-38 cells was also determined by the velocity gradient method. The ratio of the intracellular concentration to the extracellular concentration of tosufloxacin was 1.7- and 2.6-fold higher than those of ofloxacin and norfloxacin, respectively. The results indicate that the potent intracellular bactericidal activity of tosufloxacin may be due not only to its high in vitro activity but also to its ability to penetrate into cells at a high level.

Anti-Infective Agents↗
PubMed1990

Gene for parathyroid hormone-like peptide is on mouse chromosome 6.

The single-copy parathyroid hormone-like peptide gene (Pthlh) was assigned to mouse chromosome 6 using a rat PTHLH cDNA as hybridization probe in the Southern blot analysis of DNAs isolated from a panel of mouse x Chinese hamster cell hybrids. The mouse parathyroid hormone gene (Pth) has previously been assigned to mouse chromosome 7 and the PTHLH and PTH genes have also been shown to be on different chromosomes in human and rat. Therefore, despite significant amino-terminal sequence homology between the PTHLH and PTH peptides, as well as similarities in the structural organization of the human PTHLH and PTH genes, the genes encoding these peptides have discrete chromosomal locations in the mouse, rat, and man.

Animals↗
PubMed1990

Serum immunoreactive pancreatic phospholipase A2 in patients with various malignant tumors.

The high incidence (40.6%) of elevated serum pancreatic phospholipase A2 (PLA2) was demonstrated in patients with various malignancies. Serum PLA2 was significantly increased in cancer patients compared with healthy sex- and age-matched blood donors (358.4 +/- 168.0 vs. 241.7 +/- 69.0 ng/dl; p less than 0.01). No correlation was observed between serum PLA2 and carcinoembryonic antigen (CEA) in these patients. Although patients with advanced and distantly metastatic cancer of the liver, gallbladder and pancreas showed higher PLA2 levels in serum than those with early cancer, patients with other cancers showed no correlation between serum PLA2 and clinical stage. A combined assay of PLA2 and CEA increased the sensitivity of detection of cancers to 60.8%.

Amylases↗
PubMed1990

Pharmacodynamic study of F(ab')2 fragments of murine monoclonal antibody 7E3 directed against human platelet glycoprotein IIb/IIIa in patients with unstable angina pectoris.

The pharmacodynamics of intravenous bolus injections of 0.05, 0.10, 0.15, and 0.20 mg/kg of F(ab')2 fragments of the murine monoclonal antibody 7E3, 7E3-F(ab')2, directed against the glycoprotein IIb/IIIa (GPIIb/IIIa) receptor of human platelets, were studied in groups of four patients with unstable angina pectoris. With 0.20 mg/kg, the template bleeding time prolonged from 6.3 +/- 1.9 (mean +/- SD) to greater than 30 min; it subsequently decreased to 13 +/- 7.8 min after 12 h and to 8.3 +/- 1.5 min after 24 h. The number of unblocked GPIIb/IIIa receptors (preinfusion value, 32,000 +/- 3,000 per platelet) decreased to 13 +/- 7% of the preinfusion value 1 h after infusion, and then increased to 33 +/- 10% at 12 h, 44 +/- 8% at 24 h and 67 +/- 7% at 72 h. The logarithm of the bleeding time was inversely proportional with the residual GPIIb/IIIa receptors (r = 0.73, P less than 0.0001). ADP-induced platelet aggregation (measured by changes in light transmittance in percent) decreased from 60 +/- 5% before infusion to 1.5 +/- 3% 1 h after infusion; it then increased to 29 +/- 3% after 24 h and 39 +/- 6% after 72 h. Platelet counts decreased by 16% at 1 h and returned to control values within 24 h. Proportionally smaller effects were seen at lower doses of 7E3-F(ab')2. Antibody injection did not induce spontaneous bleeding. Angina was not observed during the first 12 h when the bleeding time was significantly prolonged, but occurred in 6 of the 16 patients within the next 3 d. 2 of the 16 patients developed low titers of IgG antibodies specific for 7E3-F(ab')2. Thus 7E3-F(ab')2 induces dose-related inhibition of platelet function; at a dose of 0.20 mg/kg, it causes profound inhibition of platelet aggregation and prolongation of the bleeding time, but no spontaneous bleeding.

Adult↗
PubMed1990

Irreducible dorsal dislocation of the interphalangeal joint of the great toe: report of two cases.

In this paper, we report two cases of dislocation of the hallux interphalangeal joint with interposition of the plantar plate including the sesamoid bone. These dislocations were treated with open reduction: one through lateral approach and the other through plantar approach. Plantar approach afforded repair of the plantar plate with preservation of the sesamoid bone and satisfactory result.

Adult↗
PubMed1990

Gene-encoding parathyroid hormone-like peptide: nucleotide sequence of the rat gene and comparison with the human homologue.

The single-copy gene coding for rat PTH-like peptide was isolated from a rat liver genomic DNA library. The gene spans 12 kilobases and contains four exons. Exon I encodes the 5'-noncoding region, exon II encodes the prepro region, exon III encodes the mature peptide sequence up to amino acid 139 and exon IV encodes the carboxyl-terminal two amino acids, a stop codon, and the 3'-noncoding region. Splicing of these exons yields the 1.4 kilobase mRNA which is the predominant transcript observed in the hypercalcemic rat Leydig cell tumor and several normal rat tissues. The overall exon/intron organization of the rat parathyroid hormone-like peptide (PLP) gene is similar to that of the PTH gene and emphasizes the likelihood that PLP and PTH arose from a common ancestral gene. A comparison of the single promoter region of the rat with the second promoter of the human gene indicates conserved TATA and CAAT box homologies, GC box regions (SP-1 binding sites), putative AP-2 binding sites, and a vitamin D responsive element. When compared to the seven exon human PLP gene, which uses multiple promoters and encodes three peptide isoforms, the simpler organization of the rat gene predicts, in mammals, the predominant use of a single promoter and generation of a 141-amino acid peptide as the major molecular form.

Amino Acid Sequence↗
PubMed1990

Serum interleukin 6, C-reactive protein and pancreatic secretory trypsin inhibitor (PSTI) as acute phase reactants after major thoraco-abdominal surgery.

We measured serum immunoreactive interleukin 6 (IL-6) levels in patients after major thoraco-abdominal surgery and compared them with changes in serum C-reactive protein (CRP) and pancreatic secretory trypsin inhibitor (PSTI) levels. Serum IL-6 levels were elevated earlier than serum CRP or PSTI. There were significant relationships between the peak levels of serum IL-6 and the operation time (p less than 0.05) or the volume of blood loss during surgery (p less than 0.05), showing that serum IL-6 can be a useful laboratory test for the evaluation of tissue injuries due to surgical intervention. Though there was a significant relationship between the peak levels of IL-6 and CRP (p less than 0.01), there was no relationship between the peak levels of IL-6 and PSTI.

Acute-Phase Reaction↗