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K Yonemasu

Publications and source records attributed to K Yonemasu.

At least 37 records · Page 2Linked to original sources
PubMed1991

[Detection of immune complex by C1q solid phase enzyme immunoassay].

We have developed a new and improved method for detecting immune complexes (IC) by C1q solid-phase enzyme immunoassay (CSP-EIA). The sensitivity of this method was between 0.62 micrograms/ml and 1.25 micrograms/ml, and values in normal individuals were 1.8 micrograms/ml and less. The positive rate of IC of sera in which abnormal values were detected by autoimmune disease associated laboratory examinations was 50.0% in RA (2+), 20.4% in ANA (+), 60.0% in CH50 (less than 10), 41.7% in LE latex (+). In sera of RA (2+), the higher the value of CRP detected by a semi-quantitative analysis was, the higher the frequency having abnormal high IC values was. The number of IC positive sera, in which enzyme-linked immunoglobulins were detected, was 18 of 68 (positive rate 26.5%). The number of IC positive samples in asymptomatic carriers of sera, whose titer of anti-HTLV-I antibody was positive by gelatin particle agglutination assay (PA), was 14 of 67 (pos. rate 18.4%). All of these 14 samples were high positivity of anti-HTLV-I antibody (titer greater than or equal to 256 times). In urine of some patients with urogenital diseases, IC-like substances to show positive reaction by our CSP-EIA were detected. However, any positive reaction was not detected either by an anti-C1q- or an anti-C3d method. Studies are in progress to elucidate detailed characterization of the IC-like substances.

Antigen-Antibody Complex↗
PubMed1990

C1q, a collagen-like complement subcomponent, in dermatosparactic cattle: its extracellular modification is not affected by lack of procollagen N-terminal proteinase (pN-proteinase).

C1q, a collagen-like complement protein, was purified from the serum of a dermatosparactic calf which lacks procollagen N-terminal proteinase (pN-proteinase). The specific hemolytic activity of the serum C1q from the dermatosparactic animal was identical to that of C1q from a normal calf. Gel-filtration of serum from the dermatosparactic calf, on Sepharose 6B, showed the presence of C1q-antigenic material at only one position which was identical to the elution position of normal bovine C1q. No difference, under dissociating conditions, could be seen in the size of the chains of C1q in specific immunoprecipitates isolated from the sera of dermatosparactic and normal animals, as judged by polyacrylamidegel electrophoresis (PAGE) in the presence of sodium dodecyl sulfate (SDS). The C1q from the dermatosparactic animal showed the same N-terminal amino acid and tryptic-digest peptide pattern on HPLC as C1q from the normal calf. These results strongly suggest that pN-proteinase is not involved in the extracellular processing of C1q.

Animals↗
PubMed1990

Pregnancy zone protein inhibits production of interleukin-2 but does not affect interleukin-2 receptor expression on T cell activation.

The effect of pregnancy zone protein (PZP), which exhibits increased levels in the blood during pregnancy, on T cells was examined. PZP was found to suppress DNA synthesis following stimulation with phytohemagglutinin (PHA), concanavalin A (ConA) or CD3 antigen or in the mixed lymphocyte reaction (MLR). This effect of PZP was mediated by a reduction in interleukin-2 (IL-2) production, and was abolished by exogenous recombinant IL-2 administration. PZP did not affect the proliferation of T cells following stimulation with the calcium ionophore A23187 and phorbol 12-myristate 13-acetate (TPA). These results suggest that PZP acts on the T cell surface and reduces IL-2 production, but not IL-2R expression, and does not directly affect Ca2+ influx or protein kinase C.

Calcimycin↗
PubMed1989

Characterization of C1q found in a patient with hypocomplementemic vasculitis-urticaria syndrome.

C1q, a subcomponent of the first complement component, of a 60-year-old female patient with hypocomplementemic vasculitis-urticaria syndrome (HVUS) was characterized. The C1q-precipitin activity (C1q-p) could not be detected by a routine method with 0.6% agarose in 10 mM Na-phosphate buffer containing 10 mM EDTA (pH 7.2). Hemolytic activity of her serum complement (CH50) and levels of C1 and C4 were significantly reduced at the exacerbation stage, but levels of other complement components were almost within the normal range throughout her clinical course. The specific activity of C1q at her exacerbation stage was significantly low, and its elution position on Sephacryl S-300 column was spread toward the low molecular weight in comparison with that of normal plasma. Molecular weights of the delayed fraction of C1q were estimated to be approximately 300,000 on the Sephacryl and 440,000 by the polyacrylamide gel electrophoresis (PAGE) containing sodium dodecyl sulfate (SDS) followed by immunoblotting, respectively. On reduction of her plasma, two bands with molecular weights equivalent to those of B and C chains of the normal C1q in an approximate molar ratio of 2:1 were immunostained. Plasma at her exacerbation stage showed only one precipitation line against anti-human C1q-antiserum which was completely fused with that formed between purified normal human C1q and the same antiserum. The probable structural change of the hypofunctional C1q in the case of this HVUS is discussed.

Blotting, Western↗
PubMed1988

Natural course of joint destruction and fluctuation of serum C1q levels in patients with rheumatoid arthritis.

Using the number of joints with erosion in a total of 68 joints throughout the body, we studied a population of patients with rheumatoid arthritis whose disease duration was 10-15 years. Three groups, each showing a Poisson distribution, were found: the subset with least erosive disease (LES), the subset with more erosive disease (MES), and the subset with mutilating disease (MUD). The mean number of joints with erosion was 10.9 in LES, 32.2 in MES, and 53.5 in MUD. In LES, erosive articular changes were primarily limited to the peripheral smaller joints. In MES, the larger axial joints were also involved. Almost all joints were extensively damaged in MUD. During the early period of disease, differences between the 3 groups were highly significant in the rapidity of carpal bone destruction, as assessed by the yearly reduction of carpal height ratio (P less than 0.001), and in the serum C1q level (P less than 0.001).

Adult↗
PubMed1988

Opsonic effect of fibronectin on staphylococcal phagocytosis by human polymorphonuclear leukocytes: its relative inefficiency in post-phagocytic metabolic activities and in intracellular killing.

The binding of 125I-labeled human plasma fibronectin (FN) to two strains of live Staphylococcus aureus (S. aureus) (a coagulase-positive Cowan I and a coagulase-negative Newman D2C) and the opsonic effect of FN on phagocytosis of these bacteria by human polymorphonuclear leukocytes (PMN) have been studied. 125I-FN bound to a similar extent in both staphylococcal strains. The 125I-FN-binding was significantly inhibited by human fibrinogen as well as unlabeled FN. The FN-binding was also reduced markedly by trypsinization of these bacteria, but the extent of its decrease did not correlate with their tryptic susceptibility of protein A and clumping factor. FN enhanced the uptake of these bacteria by PMN. However, its binding had no effect on superoxide anion (O2-) generation. The FN-binding definitely stimulated staphylococcal ingestion and intracellular killing by PMN, but the extent of such promotion was dissimilar between these two strains of bacteria. These results suggest that post-phagocytic metabolic activities as well as intracellular killing of these Staphylococci may also be greatly influenced by FN-unrelated factors as are other bacteria having no FN-receptors.

Agglutination↗
PubMed1988

Complement subcomponent C1q in various strains of mice. Its serum content correlates with that of immunoglobulin G.

The protein amount and the hemolytic activity of the initiating complement component (C1q) in the classical pathway, and the level of immunoglobulin G (IgG) in sera of various inbred mouse strains were measured in parallel with those in sera of closed colony mice. C1q levels were significantly high in male A/He and C57BL/10Sn mice, and conspicuously high in female C57BL/10Sn mice. In these strains and C57BL/6J mice of both sexes, IgG levels were also significantly high. IgG levels were strikingly high in female NZB mice and NZW mice of both sexes. On the other hand, both C1q and IgG levels were conspicuously low in BALB/c mice of both sexes and in male CBA mice, and surprisingly low in BALB/c-nu (nude) mice of both sexes. A significant correlation was observed between serum levels of C1q and IgG. The C1q specific activity, however, was equivalent in all serum samples with approximately 2 x 10(13) effective molecules/mg. The subunit composition of C1q analyzed by polyacrylamide gel electrophoresis was well comparable within all strains of mice tested. These results may suggest that mouse serum C1q does not have any phenotypic polymorphism.

Animals↗
PubMed1987

Two proteins with gamma-carboxyglutamic acid in frog bone: isolation and comparative characterization.

Two gamma-carboxyglutamic acid-containing proteins were purified from neutral (pH 7.5) EDTA-extract of frog, Rana catesbiana, cortical bone by Sephadex G-75 gel filtration, DEAE-Sephadex A-25 chromatography and successive hydroxyapatite column chromatography. These two bone gamma-carboxyglutamic acid-containing proteins, termed osteocalcin, P-1 and P-2, had molecular weights of about 5100 and 4900, respectively, based on their amino-acid composition. Both species of osteocalcin have two gamma-carboxyglutamic acid residues, one disulfide bond, but there was no 4-hydroxyproline in either molecule. Each N-terminus of both proteins was acetylated and each C-terminal amino acid was lysine. The isoelectric points of P-1 and P-2 are 4.02 and 3.91, respectively, and their pI values shifted to more neutral pH in the presence of calcium ions. Equilibrium dialysis has indicated that each of these two proteins binds specifically 2 mol Ca2+, and nonspecifically more, 4-5 mol, Ca2+ in 0.02 M Tris-HCl/0.15 M NaCl (pH 7.4), at 4 degrees C. By the best-fitted calculation, P-1 had one high affinity Ca2+-binding site (Kd1 = 0.17 mM) and one lower affinity site (Kd2 = 0.29 mM), and P-2 contained one high affinity site (Kd1 = 0.154 mM) and one lower affinity site (Kd2 = 0.67 mM).

1-Carboxyglutamic Acid↗
PubMed1987

Serum levels of bone Gla-protein in normal humans and in patients with chronic renal failure.

Levels of serum bone Gla-protein (BGP) were evaluated in 372 normal Japanese subjects (164 males, 208 females), ranging in age from 14 to 87 years, and in 194 patients with chronic renal failure, 181 of whom were on maintenance hemodialysis. The age-dependent serum BGP levels (mean +/- SD) determined by radioimmunoassay in normal subjects under 20 years old were 27.1 +/- 20.5 ng/ml, and 10.2 +/- 5.8 ng/ml in older subjects. Mean serum BGP increased significantly in patients with hemodialysis (35.1 +/- 24.3 ng/ml) and in patients with nonhemodialysis chronic renal failure (20.6 +/- 14.2 ng/ml). The mean BGP levels showed a trend toward higher values in the younger renal failure patients. However, the difference to the values of older patients did not reach a level of statistical significance. There was a significant (r = 0.84, p less than 0.001) positive correlation between serum BGP and serum creatinine for the nonhemodialysis group alone, but not for hemodialysis patients alone. A correlation was also observed between serum BGP and serum C-PTH in hemodialysis patients. Our results suggest that the serum BGP elevation in patients with chronic renal failure probably reflects not only decreased renal clearance but also increased bone formation.

Adolescent↗
PubMed1986

Purification, identification and characterization of chicken C1q, a subcomponent of the first component of complement.

A component, having the equivalent haemolytic activity to that of human complement subcomponent C1q, was purified by a combination of precipitation with EGTA, gel filtration, ion exchange and adsorption chromatography from chicken serum. Yields ranged from 8 to 15 mg/litre of serum. The finally purified preparation generates full Cl haemolytic activity when assayed with human complement subcomponents C1r and C1s, and have been identified as chicken C1q. The molecular weight of undissociated C1q, as estimated on polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate (SDS), is 504,000. Under dissociating but non-reducing conditions, the C1q was shown to consist of 2 subunits having molecular weights of 52,700 and 51,200 in a molar ratio of 2:1. On reduction, the 52,700 molecular weight subunit gave chains with molecular weights of 25,900 and 24,800 in equimolar ratio, and the 51,200 molecular weight subunit decreased to 24,800. The C1q contains hydroxyproline, hydroxylysine, a high percentage of glycine and approximately 7% carbohydrate. Collagenase digestion of C1q caused a rapid loss of haemolytic activity and produced much smaller peptide fragments.

Amino Acids↗
PubMed1984

A study of the role of the asparagine-linked sugar chains of human complement subcomponent C1q in its biological activities.

The sialic acid residues were removed from asparagine-linked sugar chains on the C-terminal non-collagenous globular regions of human C1q by sialidase digestion. Both the haemolytic activity and the binding ability to immunoglobulin G (IgG) (Fc-binding ability) of C1q were unimpaired, even after the complete removal of sialic acid from these sugar chains. On the other hand, the rate of disappearance of C1q from the circulation was greatly accelerated by its desialylation, that is, the radioactivity of the infused intact and desialylated C1q was reduced to half for 200 min and for 140 min in the circulation of rats, respectively. A mixture of entire asparagine-linked sugar chains consisting of neutral, monosialyl and disialyl oligosaccharides was isolated from the intact C1q molecule by hydrazinolysis. The oligosaccharide-mixture isolated, after NaBH4 reduction, was added to assay system of C1q, but neither the haemolytic activity nor the Fc-binding ability was influenced.

Antigen-Antibody Complex↗
PubMed1984

Comparative studies on biological activities of subcomponents C1q of the first component of human, bovine, mouse and guinea-pig complement.

Both the haemolytic activity and the binding ability to immunoglobulin G(IgG) (Fc-binding ability) were comparatively assayed among human, bovine, mouse and guinea-pig C1q. The haemolytic activity was measured by using the sensitized sheep erythrocytes with rabbit immunoglobulin M(IgM)- or IgG-haemolysin. The Fc-binding ability was assayed by using immune complexes made of rabbit IgG-antibody against human serum albumin as well as agglutination of latex particles coated with human, bovine or rabbit IgG (IgG-latex). The specific haemolytic activity was comparable with between bovine and mouse C1q, while those of guinea pig and human C1q were significantly lower than those of the others. Only the human and mouse C1q showed significantly positive agglutinating activity of human or bovine IgG-latex. In the case of the use of rabbit IgG-latex, each of these C1q gave much weaker agglutination. On the other hand, the ability of all these C1q to bind to Fc of immune complexes specifically was almost comparable. The discrepancy in specific activities between the haemolysis and the Fc-binding ability may suggest that these two biological activities are not always correlative and that these are independent biological phenomena.

Animals↗
PubMed1984

Serum C1q levels as a prognostic guide to articular erosions in patients with rheumatoid arthritis.

C1q was measured serially by single radial immunodiffusion in 54 rheumatoid arthritis (RA) patients over a period of more than 5 years, and values were correlated with laboratory, radiographic, and clinical findings. The number of joints with erosion (NJE) was determined retrospectively from radiographs of patients who had RA of greater than 7 years duration. In patients with clinically "burned out" RA, C1q levels were not statistically different from those of healthy adults. During the period of active disease, each patient's C1q level remained very constant, irrespective of erythrocyte sedimentation rate, C-reactive protein (CRP) level, or whether the RA was active or in remission. No sustained correlation was found between the C1q level and the other 2 acute phase reactants, but patients with C1q levels of at least 250 micrograms/ml showed a positive CRP over a period of years, in contrast to those with C1q levels below 250 micrograms/ml. Patients with an initial C1q above 250 micrograms/ml had more erosive RA when compared with those having C1q levels below 250 micrograms/ml. These data suggest that active RA can be classified into two subsets by C1q levels, one with persistent inflammation and a high NJE and another without persistent inflammation and with a low NJE.

Adolescent↗