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Biomedical subjects

A Abe

Publications and source records attributed to A Abe.

At least 235 records · Page 13Linked to original sources
PubMed1989

Two distinct subtypes of the HLA-DRw12 haplotypes in the Japanese population detected by nucleotide sequence analysis and oligonucleotide genotyping.

We determined the DNA sequence of the enzymatically amplified second exon of the DRB1 gene of the Drw12 haplotypes derived from three Japanese donors and found two distinct subtypes of the DRw12 haplotype. The two subtypes, designated DRw12a and DRw12b, had single-base substitutions that predicted one amino acid change at residue number 67. The sequence of the DRw12a and DRw12b subtypes differed from those of the other DR haplotypes, but in the first hypervariable region of the DRB1 gene the sequences were identical to those of the DRw8(Dw8.1) and DRw8(Dw8.3) haplotypes. The DRw12a and DRw12b subtypes were detected in a wide range of Japanese donors by genotyping with sequence-specific oligonucleotide probes synthesized according to the DNA sequences of the two subtypes. Results of this study demonstrated that the DRw12 haplotypes in the Japanese population are genetically diverse, as many other DR haplotypes are.

Asian People↗
PubMed1989

Lipoprotein(a) in nonhuman primates. Presence and characteristics of Lp(a) immunoreactive materials using anti-human Lp(a) serum.

Lipoprotein(a) (Lp(a] immunoreactive materials were examined in serum samples from 77 nonhuman primates of 24 species by Ouchterlony's double diffusion procedure and an enzyme-linked immunosorbent assay (ELISA) using rabbit antisera to human Lp(a). The precipitates obtained with sera from orang-utan and chimpanzee formed reactions of complete identity with the Lp(a) precipitate with human serum. When sera from Old World monkeys and human subjects were tested in wells next to each other, spurs developed between the 2 precipitates, indicating that Lp(a)-like lipoproteins in Old World monkeys have partial identity with human Lp(a). Lp(a) immunoreactive materials were identified in association with lipids by means of fat staining of the precipitates. On the other hand, reactants which could be precipitated with anti-human Lp(a) sera were not detectable in prosimians and New World monkeys. These results suggest that serum Lp(a)-like lipoprotein is phylogenetically acquired in Old World monkeys. However, the possibility that the structures of serum Lp(a)-like lipoproteins in prosimians and New World monkeys are too different to react with anti-human Lp(a) sera cannot be ruled out.

Animals↗
PubMed1989

Transient changes of serum lipoprotein(a) as an acute phase protein.

Serum lipoprotein(a) (Lp(a)) was serially determined after acute attacks of myocardial infarction and after surgical operations. Acute phase proteins, such as C-reactive protein, alpha 1-acid glycoprotein, alpha 1-antitrypsin and haptoglobin, increased rapidly and markedly after the episodes. Initial values of serum Lp(a) concentrations were almost the same in both groups. Increases in serum Lp(a) levels were also observed during the first few days, with a return to the initial levels after more than 1 month. The periods for reaching maximal levels of acute phase proteins were similar in both groups of patients. On the contrary, the period required for Lp(a) to reach the maximal level in the myocardial infarction group was significantly longer than in the post-operative group. The present study suggests that Lp(a) has the characteristics of an acute phase reactant and may play an important role in recovery from tissue damage.

Acute-Phase Proteins↗
PubMed1989

Oligonucleotide-genotyping as a method of detecting the HLA-DR2 (DRw15)-Dw2, -DR2 (DRw15)-Dw12, -DR4-Dw15, and -DR4-D"KT2" haplotypes in the Japanese population.

We synthesized pairs of four different oligonucleotides, F22, F29, F42, and F158, to analyse the HLA-DR2 (DRw15) and -DR4 haplotypes in the Japanese population. After enzymatically amplifying the HLA-DRB1 gene, we hybridized the oligonucleotide probes with DNA extracted from 42 donors. Hybridization was completed between F22 and the DNA of haplotype DR2 (DRw15)-Dw2, between F29 and the DNA of DR2 (DRw15)-Dw12, between F42 and the DNA of DR4-D"KT2", and between F158 and the DNA of DR4-Dw15. In keeping with the nucleotide sequences of the probes, F29 hybridized also with DNA from the DR9-Dw23 haplotype and F158 with that from some of the DRw8 haplotypes (DRw8-Dw8.3) in the Japanese population. Results of this study demonstrate that the four oligonucleotides make useful probes for detecting the haplotypes above.

Asian People↗
PubMed1989

[Sequential changes in plasma lipoprotein(a) as acute phase protein after myocardial infarction and surgery group].

The plasma lipoprotein(a), apo AI, apo B, and acute phase proteins, were studied in 21 patients with myocardial infarction and in 11 patients after surgery. In the both groups, C-reactive protein showed a rapid increase, and alpha 1 acid glycoprotein, alpha 1 antitrypsin and lipoprotein(a) followed by a moderate increase and restored to normal values after one month. Lipoprotein(a) increased to a maximum on day 11 in the myocardial infarction group, and on day 8 in the surgery group. Only slight changes in apolipoprotein AI and B were noted. We speculate that lipoprotein(a) is an acute phase protein that plays an important roles in recovery from trauma. Recently it was reported that the amino acid sequence of apolipoprotein(a) is partly identical to that of plasminogen. This sequence suggests that lipoprotein(a) and plasminogen are related immunochemically. We examined by immunoblotting technique whether our antibody for lipoprotein(a) is influenced by a plasminogen in plasma. By enzyme-linked immunosorbent assay, it was found that the purity of plasminogen does not influence determination of lipoprotein(a).

Acute-Phase Proteins↗
PubMed1989

[Interstitial pneumonia (IP) in bone marrow transplantation in leukemia--120 cases analysis in Nagoya Bone Marrow Transplantation Group].

Results of the bone marrow transplantation (BMT) for 120 cases of leukemia, which were done in nine institutes in Nagoya (Nagoya Bone Marrow Transplantation Group) last ten years, were analyzed to determine the factors associated with an increased risk of developing interstitial pneumonia (IP). IP developed 49 out of 120 patients (49.8%) and case fatality rate was 63.3%. The median time from transplantation to onset of IP was 81 days (range 13-575 days), in 30 out of 49 cases (61.2%), this complication developed within 100 days after transplantation. Of the 49 patients who developed IP, cytomegalovirus (CMV) infection was associated in 18 cases (36.7%), no cases of P. carinii infection was detected. Five factors were associated with an increased risk for developing IP, (1) older age (greater than or equal to 47.0%: less than 10 y. 10.0%) (p less than 0.01) (2) disease stage at BMT (non-remission 76.2%: remission 32.5%) (p less than 0.01) (3) presence of acute GVHD ((+) 52.5% (-) 28.8%) (p less than 0.05) (4) onset day after BMT (less than or equal to 100 days 61.2%: greater than 100 d. 38.8%) (p less than 0.01) (5) sex matching between donor and patient (sex match 28.8%: sex mismatch 57.1%) (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Expression of a human P-450IIC gene in yeast cells using galactose-inducible expression system.

A cDNA of a human liver cytochrome P-450, corresponding to P-450 human-2, was expressed in Saccharomyces cerevisiae cells by the use of a galactose-inducible expression vector containing the GAL7 promoter and terminator. In Western blots using anti-P-450 human-2 IgG, a single band, which exhibited mobility identical to that of authentic P-450 human-2 purified from human liver, was detected in microsomes of the yeast cells. The amount synthesized in yeast was estimated to be approximately 1% of the total cell protein, and approximately 25% of the cytochrome existed in the holoenzyme state. Microsomes from the P-450 human-2-producing yeast showed a catalytic activity towards benzo(a)pyrene, and the activity was significantly enhanced by the addition of purified NADPH-cytochrome P-450 reductase. The yeast microsomes also catalyzed (S)-mephenytoin 4-hydroxylation but not the demethylation. The present results indicate that the yeast cells containing P-450 human-2 cDNA synthesize a functionally active form of the enzyme, the chemical and catalytic properties of which are identical to those of the human liver preparation.

Antigen-Antibody Reactions↗
PubMed1989

Sensitive, direct colorimetric assay for copper in serum.

We have developed a sensitive procedure for determination of serum copper by use of the color reagent 4-(3,5-dibromo-2-pyridylazo)-N-ethyl-N-sulfopropylaniline. After mixing serum sample and reagent, and incubating at 37 degrees C for 5 min, we measure the absorbance of the resulting chelate complex at 580 nm (molar absorptivity, 80,000 L.mol-1.cm-1). Results of the method varied linearly with copper concentration to at least 5 mg/L; the lower limit of detection was 0.1 mg/L. Within-run CVs were 1.6% and 3.3% for copper concentrations of 1.03 and 0.72 mg/L, respectively (n = 10 each). Between-run CV was 2.8% at 1.22 mg/L (n = 14). Results of the proposed method (y) correlated well with those determined by standard atomic absorption spectrophotometric techniques (x): y = 0.99x - 0.02 mg/L; Syx = 0.08; r = 0.977; n = 56. Iron, zinc, cadmium, cobalt, and lead do not interfere.

Aniline Compounds↗
PubMed1989

Effect of forskolin on cytosolic Ca++ level and contraction in vascular smooth muscle.

The effects of forskolin, an activator of adenylate cyclase, on cytoplasmic Ca++ level ([Ca++]cyt) measured simultaneously with muscle tension using fura-2-Ca++ fluorescence were examined in isolated smooth muscle of rat aorta. Forskolin decreased muscle tension and [Ca++]cyt in resting aorta whereas both norepinephrine and high K+ solution produced sustained increase in muscle tension and [Ca++]cyt. Addition of forskolin during the sustained contractions decreased muscle tension more strongly than [Ca++]cyt. Norepinephrine-induced contraction was more sensitive to forskolin than high K+-induced contraction. The inhibitory effect of forskolin was attenuated when the concentration of norepinephrine or K+ was increased. Cumulative addition of norepinephrine or K+ induced a concentration-dependent increase in both [Ca++]cyt and muscle tension and a positive [Ca++]cyt-tension correlation was observed. In the presence of 0.1 microM forskolin, the norepinephrine-induced increments in [Ca++]cyt and muscle tension were inhibited without changing the [Ca++]cyt-tension relationship. In the presence of a higher concentration (1 microM) of forskolin, muscle tension was inhibited more strongly with only a small additional decrease in [Ca++]cyt resulting in a shift of the [Ca++]cyt-tension relationship. Norepinephrine induced transient increments in [Ca++]cyt and muscle tension in Ca++-free solution and forskolin inhibited these changes. These results suggest that forskolin has concentration-dependent inhibitory effects on vascular contractility to decrease [Ca++]cyt at lower concentrations and to decrease the sensitivity of contractile elements to Ca++ at higher concentrations.

Animals↗
PubMed1988

Enzyme-linked immunosorbent assay of lipoprotein(a) in serum and cord blood.

We have developed a new sensitive method for quantifying lipoprotein(a) (Lp(a] in human serum, using a 'sandwich' type noncompetitive enzyme-linked immunosorbent assay (ELISA). The solid-phase used was a polystyrene plate. The anti-Lp(a) antibody-enzyme conjugate was labelled by linking Fab' fragments to peroxidase (EC 1.11.1.7) by the maleimide method. The minimum detectable concentration was 0.5 ng/well. Routinely, the assay was carried out with 1,000-fold diluted serum, and Lp(a) was quantified between 4.0 and 500 mg/l. Within-run coefficients of variation (CVs) ranged from 3.5% to 10.4% and between-run CVs from 5.0% to 11.1%. Results by the ELISA were in good agreement with those by radial immunodiffusion (r = 0.955). The distribution of Lp(a) in serum from 820 healthy donors was highly skewed: mean 141.1 mg/l, medium 97.9 mg/l. In cord blood, the mean and median were 15.6 and 9.8 mg/l, respectively. This ELISA for Lp(a) has the advantages of being highly sensitive and specific, simple to perform, and does not use radioisotopes.

Adolescent↗
PubMed1988

GAL11 protein, an auxiliary transcription activator for genes encoding galactose-metabolizing enzymes in Saccharomyces cerevisiae.

Normal function of the GAL11 gene is required for maximum production of the enzymes encoded by GAL1, GAL7, and GAL10 (collectively termed GAL1,7,10) in Saccharomyces cerevisiae. Strains bearing a gal11 mutation synthesize these enzymes at 10 to 30% of the wild-type level in the induced state. In a DNA-RNA hybridization experiment, the gal11 effect was shown to be exerted at the transcription level. Yeast cells bearing the gal11 mutation were shown to grow on glycerol plus lactate more slowly than the wild type. We isolated recombinant plasmids carrying the GAL11 gene by complementation of the gal11 mutation. When the GAL11 locus was disrupted by insertion of the URA3 gene, the resulting yeast cells (gal11::URA3) exhibited phenotypes almost identical to those of the gal11 strains, with respect to both galactose utilization and growth on nonfermentable carbon sources. Deficiency of Gal4, the major transcription activator for GAL1,7,10, was epistatic over the gal11 defect. The Gal11 deficiency lowered the expression of GAL2 but not that of MEL1 or GAL80; expression of these genes is also known to be dependent on GAL4 function. We determined the nucleotide sequence of GAL11, which is predicted to encode a 107-kilodalton protein with stretches of polyglutamine and poly(glutamine-alanine). An alpha-helix-beta-turn-alpha-helix structure was found in a distal part of the predicted amino acid sequence. A possible role of the GAL11 product in the regulation of galactose-inducible genes is discussed.

Amino Acid Sequence↗
PubMed1988

Inhibitory effects of forskolin on vascular smooth muscle of rabbit aorta.

Effects of forskolin on the contractions in rabbit aorta were examined. The sustained contraction induced by 10(-6) M norepinephrine was inhibited by 10(-8)-10(-5) M forskolin in a concentration-dependent manner. In the high K+-depolarized and verapamil-treated aorta, the norepinephrine-induced sustained contraction was similarly inhibited by forskolin. However, forskolin showed only a slight inhibitory effect on the sustained contraction induced by 65.4 mM KCl. Forskolin inhibited the increase in Ca2+ influx due to norepinephrine, but not that due to high K+. In a Ca2+-free solution, 10(-6) M norepinephrine induced a transient contraction which is due to Ca2+ release from the store site. This contraction was inhibited by 3 X 10(-7)-10(-5) M forskolin. However, caffeine-induced transient contraction was not inhibited by 10(-5) M forskolin. 45Ca2+ in a cellular site was released by 10(-6) M norepinephrine or 10 mM caffeine. Forskolin inhibited the Ca2+ release induced by norepinephrine, but not that by caffeine. Forskolin increased the tissue cAMP content in resting, 10(-6) M norepinephrine-treated or 65.4 mM K+-treated aorta. It is concluded that forskolin inhibits the norepinephrine-induced sustained contraction by relatively selectively inhibiting the receptor-linked Ca2+ channel, and it inhibits the norepinephrine-induced transient contraction by inhibiting Ca2+ release from the cellular store.

Animals↗