Coagulation-fibrinolytic analysis in patients with lung cancer.
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Blood Coagulation Disorders↗
Biomedical subjects
T Seya
Publications and source records attributed to T Seya.
A fluorometric method for determination of C3b inactivator.
A simple method for the determination of C3b inactivator in human plasma was investigated. Fluorescent-labeled C3, which was prepared by treatment with methylamine and a fluorescent thiol reagent, N-(dimethylamino-4-methylcoumarinyl)-maleimide, was used as the substrate. Diluted human plasma is incubated with fluorescent C3, reduced with 2-mercaptoethanol, and subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis. The fluorescent cleavage product is then determined by scanning the gels with a fluorospectrophotometer. This method is simple and sensitive enough to determine C3b inactivator activity in 1 microliter of human plasma.
Complement C3b Inactivator Proteins↗
Role of dextran sulfate in urokinase therapy and evaluation of the effects by estimation of plasmin inhibitor, fibrinogenolytic degradation products, and fibrinolytic degradation products.
The present study was concerned with changes in APTT and coagulation-fibrinolytic inhibitors in 2 groups of patients receiving either UK with heparin or UK with heparin and dextran sulfate (DS). APTT just after UK treatment showed a significant prolongation in patients receiving combination treatment with DS, but contrarily a shortening in patients receiving those with DS. This result indicated the usefulness of DS combination in UK treatment. There was a marked difference between the responses of alpha 2-PI and antiplasmin to the treatment, presumably as a result of immune complex formation of the alpha 2-PI with plasmin. However, no marked difference in alpha 2-PI and AT-III existed both just after and at 24 hours after UK treatment in patients receiving UK (240,000 units) with both heparin and DS and those receiving UK (480,000 units) with heparin. Those results suggest that the dosage of UK can be reduced by combination of DS. Successful UK treatment in clinical cases resulted in a decrease of alpha 2-PI and an increase of fibrinogenolytic or fibrinolytic degradation products. For these reasons, effective UK treatment appears to require combination with DS and several treatment days under the condition with a decrease of alpha 2-PI (50%) and fibrinogenolysis with fibrinolysis, which are followed by administrations of UK.
Antithrombin III↗
Limited proteolysis of the third component of human complement, C3, by heat treatment.
Human C3 is composed of two disulfide-linked polypeptide chains, termed alpha chain (with a molecular weight of 110,000) and beta chain (with a molecular weight of 75,000). When 3C was heated at above 50 degrees C and at neutral pH, a single peptide bond in the alpha chain was selectively cleaved to yield two alpha chain fragments with molecular weights of 75,000 and 44,000. The two alpha chain fragments and intact beta chain are originally connected by disulfide linkages but are gradually dissociated upon prolonged heat treatment. The dissociation seems to be caused by thiol-disulfide interchange reactions, since the dissociation was prevented by the addition of monoiodoacetic acid and only 1 mol of thiol group was determined to be newly generated upon heat treatment of C3. The heat-induced C3 cleavage reached a plateau when almost 1 mol of thiol group appeared. In addition, the heat-induced C3 cleavage was prevented by pretreatments with C3 convertase and methylamine, which are known to cleave the thioester linkage in the side chain of C3. Thus, the thioester linkage, which is the latent reactive site in C3 and which, upon activation of C3, forms an ester linkage with cell surfaces, seems to make a specific peptide bond extremely heat-labile.
Complement C3↗
Assay of heparin in plasma using a chromogenic substrate and its clinical applications.
The concentration of heparin in plasma was measured using a chromogenic substrate. It appeared that the measurement of heparin concentration in plasma was important in therapeutic control and evaluation of heparin. There was a correlation between the activated partial thromboplastin time (APTT) and heparin concentration in plasma, but since the gradients of regression line differed in each of the cases, measurement of APTT alone would give a different estimate of heparin concentration in each case. Fibrinopeptide A (FPA) is considered as the best indicator for evaluatin of therapeutic effects of heparin. Therapeutic heparin concentrations were defined as ranging from 0.2 to 1.2 IU/ml because the normalization of FPA was observed and there happened no hemorrhagic accidents in that range.
Adult↗
[Embolic pneumopathy induced by tissue thromboplastin (author's transl)].
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Animals↗
Regulatory system of guinea-pig complement C3b: tests for compatibility of guinea-pig factors H and I with human factors.
Two proteins that are involved in cleavage of methylamine-treated C3 of guinea-pig origin (C3(MA)gp) have been isolated from guinea-pig serum. One of them functioned as a cofactor of human factor I (Ihu) for cleavage of C3(MA)gp and its molecular size was 150 kDa. The other was functionally pure and able to cleave C3(MA)gp together with human factor H (Hhu). They appear to be analogous to human factors H and I in the guinea-pig and will be referred to as Hgp and Igp. Methylamine-treated human C3 [C3(MA)hu] was not a compatible substrate for Hgp or Igp: little cleavage of C3(MA)hu was observed if human factor H (Hhu) or I was substituted with the guinea-pig counterpart. C3(MA)gp, on the other hand, served as a substrate, though less efficiently, for Hhu and Ihu. Human C4b-binding protein (C4bp) and membrane cofactor protein (MCP) as well as Hhu could participate in cleavage of C3(MA)gp by Igp or Ihu. In these assays, C3(MA)gp was degraded again less efficiently than C3(MA)hu. Interestingly, human C3b/C4b receptor (CR1) mediated factor I-dependent cleavage of C3(MA)hu and C3(MA)gp to a similar extent regardless the sources of factor I. These results suggest that factor I-dependent C3b regulatory system is species-specific except in the case of CR1, which may function as a cofactor irrespective of species.
Animals↗
Analysis of C5b-8 binding sites in the C9 molecule using monoclonal antibodies: participation of two separate epitopes of C9 in C5b-8 binding.
C5b-8 binding sites in C9 were examined using mAbs raised against C9. Among 16 mAbs, two, designated P40 and X197, blocked C9-mediated EAC1-8 lysis. C9 pretreated with the mAbs failed to bind to EAC1-8 at 4 degrees C. In addition, the mAbs became inaccessible to the C9 that had been incorporated into EAC1-8 at 4 degrees C. These findings suggest that C9 binding to EAC1-8, but not its membrane spanning or polymerization, is blocked by mAbs. By immunoblotting analysis using alpha-thrombin proteolytic fragments derived from C9 [a N-terminal fragment of mol. wt 25,000 (C9a) and a C-terminal one of mol. wt 37,000 (C9b)] and tryptic fragments of C9 (mol. wts 53,000 (C9a') and 20,000 (C9b')), the epitopes of P40 and X197 were mapped to the N-terminal and C-terminal regions of C9b, respectively. Both P40 and X197 bound to the C9 polymerized with Zn2+ in the fluid phase, whereas X197 but not P40 reacted with the membrane attack complex (MAC) formed on membranes. The results suggest that two distinct epitopes are involved in C9 binding to EAC1-8, and behave in a different manner for globular C9 bound to EAC1-8 at 4 degrees C, C9 assembled in MAC, or poly-C9 induced by Zn2+. These mAbs may be useful in clarifying the conformational states of C9 and in analyzing the molecular interaction between C9 and its inhibitors.
Amino Acid Sequence↗
The regulation of membrane cofactor protein (CD46) expression in transgenic mice: the importance of the first 125 BP of the 3' untranslated region.
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Actins↗
Homologous complement activation on drug-induced apoptotic cells from a human lung adenocarcinoma cell line.
Activation of the alternative pathway of homologous complement (C) was observed in a human lung adenocarcinoma cell line, CADO 43, after the cells had become apoptotic following treatment in vitro with vincristine and predonisolone. Deposition of C3b and C3bi on the serum-treated apoptotic cells was revealed by flow cytometry with anti-C3b and -C3bi-specific antibodies and immunoblotting with anti-C3 antibody immunoprecipitates extracted from solubilized fractions of serum-treated apoptotic cells. Two molecular mechanisms were found to be responsible for this post-apoptotic C-activation. Firstly, all C regulators, decay accelerating factor (DAF), membrane cofactor protein (MCP) and C3b/C4b receptor (CR1), were diminished on the cell surface concomitantly with the apoptotic process. Secondly, unidentified molecules which potentially activate homologous C and accept C3b/C3bi fragments became expressed on the cell surface during the apoptotic process. These findings may explain the mechanism whereby tumor cells are efficiently eliminated through chemotherapy.
Adenocarcinoma↗
The mouse factor H allotypes with multiple amino acid replacement, H.1 and H.2 show indistinguishable co-factor activity for factor I.
The authors report the functional analysis of the purified mouse factor H allotypes H.1 and H.2, which were clearly distinguished from each other by an immunodiffusion test. Both allotypes acted as a co-factor for factor I in cleaving mouse C3b and we found no significant difference between their activities. The results strongly suggest that the function of mouse factor H for the co-factor activity has been well conserved between two allotypes.
Alleles↗
Establishment and characterization of a human rectal neuroendocrine carcinoma xenograft into nude mice.
BACKGROUND: Carcinoid tumor has been recognized as having a much wider spectrum than was previously thought. Now the term 'neuroendocrine carcinoma' (NEC) has been suggested to describe malignant epithelial tumors of neuroendocrine differentiation. Its biological behavior has not been well characterized because of the lack of in vivo models. MATERIALS AND METHODS: A metastatic inguinal lymph node from rectal NEC was used for heterotransplantation into nude mice. Histochemical and immunohistochemical stainings were performed in addition to ultrastructural investigations. Hormonal peptides were measured in both xenograft tumor tissue and serum. RESULTS: We succeeded in heterotransplantation of human rectal NEC into nude mice. To date tumorigenicity has been retained for approximately 38 months. The xenograft tumor was a histopathologically identical tumor. The immunohistochemical expression of the various hormonal peptides in the xenograft was essentially the same as that of the primary rectal tumor. Tissue and serum hormonal peptides in the xenografted tumor were measured. Serum glucagon and serotonin were significantly higher than in control mice. CONCLUSIONS: The expression of various hormonal peptides in NEC may vary depending on the surrounding environment. The establishment of NEC in xenografts provides a model for further study of the biological behavior of NEC, as well as the in vivo effects of chemotherapeutic agents on tumor growth and the release of hormonal peptides.
Animals↗
Correlation between metastatic potency and the down-regulation of E-cadherin in the mouse hepatoma cell lines G-1 and G-5.
Cell-cell adhesiveness, involving the adherens junction system including homophilic adhesion of cadherin and intracellular catenins, is a critical factor for tumor cell invasion and metastasis. We evaluated the levels of E-cadherin and beta-catenin in hepatoma cell sublines with high and low metastatic capacities. Stimulation of these cells with serum growth factors for more than 3 h after 24 h of starvation caused decreases in levels of E-cadherin and beta-catenin in the subline with high metastatic capacity, G-5. In contrast, no significant changes were observed in the subline with low metastatic capacity, G-1. Concomitantly with the decreases in E-cadherin and beta-catenin levels, G-5 cells were dissociated and detached from the culture dish, although G-1 cells again showed no morphological alterations. These in vitro results reflected the in vivo metastatic potencies of these hepatoma sublines, and further suggested the importance of the adherens junction system in determining metastatic potency of these parenchymal tumor cell lines as in epithelial/endothelial tumors.
Animals↗