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Biomedical subjects

B R Binder

Publications and source records attributed to B R Binder.

At least 109 records · Page 6Linked to original sources
PubMed1994

Effect of notoginsenoside R1 on the synthesis of tissue-type plasminogen activator and plasminogen activator inhibitor-1 in cultured human umbilical vein endothelial cells.

Among other Chinese herb drugs, Panax notoginseng is used to treat cardiovascular diseases. To elucidate any possible effects of this drug on the hemostatic system in vitro, we analyzed the influence of one of its major active constituents on fibrinolytic parameters of cultured human umbilical vein endothelial cells (HUVECs). When confluent cultures of HUVECs (passages 2 to 3) were conditioned with purified notoginsenoside R1 (NR1), a dose- (0.01 to 100 micrograms NR1/mL) and time-dependent increase in tissue-type plasminogen activator (TPA) synthesis was observed, which was significant from 0.1 microgram NR1/mL and from 6 hours of incubation with 100 micrograms NR1/mL on. TPA antigen increased from 3.9 +/- 0.2 ng per 10(5) cells per 24 hours to 8.0 +/- 0.5 ng per 10(5) cells per 24 hours on addition of 100 micrograms NR1/mL. In contrast, no change in urokinase-type plasminogen activator and plasminogen activator inhibitor-1 (PAI-1) antigen synthesis was seen. There was also no effect of NR1 on PAI-1 deposition in the extracellular matrix. As judged from fibrin autography and reverse fibrin autography, TPA activity and TPA-PAI-1 complexes reached a maximal stimulation of more than threefold and twofold, respectively, at a concentration of 100 micrograms NR1/mL in conditioned media. On the contrary, NR1 induced a more than fivefold decrease in PAI-1 activity at the same concentration of NR1 in conditioned media. On Northern blot analysis of RNA obtained from NR1-stimulated and control HUVECs, NR1 induced a significant increase in TPA mRNA (192% of control value at 100 micrograms NR1/mL) while PAI-1 mRNA remained unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Antineoplastic Agents, Phytogenic↗
PubMed1994

Fibrinogen, t-PA, and PAI-1 plasma levels in patients with pulmonary hypertension.

We measured fibrinogen levels as well as the fibrinolytic parameters tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor 1 (PAI-1) in plasma samples obtained at basal conditions and after stimulating the fibrinolytic system by venous occlusion (VO). Samples were taken from patients with primary pulmonary hypertension (PPH), with secondary thromboembolic pulmonary hypertension (SPHTH), with secondary pulmonary hypertension due to congenital heart disease with Eisenmenger's reaction (SPHCD), and from healthy control individuals (CON). Fibrinogen levels were not significantly different between the groups with PPH and SPHTH or between SPHCD and CON. The latter groups, however, exhibited significantly lower fibrinogen plasma levels compared with PPH or SPHTH (p < 0.01). Basal plasma levels of t-PA antigen, t-PA activity, and PAI-1 activity, respectively, did not differ significantly between the study groups. After VO, mean t-PA activity levels increased to a higher extent in control subjects compared with patients with PPH, or SPHTH, or SPHCD, with significant differences only between CON and SPHTH or CON and PPH (p < 0.03). Patients with PPH and SPHTH exhibit both increased fibrinogen plasma levels and a diminished fibrinolytic response compared with healthy subjects. Moreover, the fibrinogen plasma levels in patients with SPHCD are in normal range, and the fibrinolytic response is similar to CON compared with PPH and SPHTH, thus indicating the existence of a comparable prothrombotic situation in patients with PPH and SPHTH.

Adult↗
PubMed1994

Secretory response of the vessel wall to DDAVP and venous occlusion in von Willebrand's disease.

The aim of this study was to compare the secretory response of the vascular wall in vivo to DDAVP (i.v. 0.3 microgram/kg, 30 min) and to venous occlusion (VO, 20 min) in control healthy subjects, patients with von Willebrand's disease type I (vWd I) and patients with von Willebrand's disease type III (vWd III). In controls (n = 10) and vWd I (n = 12), DDAVP induced a 2 to 3-fold rise in plasma von Willebrand factor antigen (vWf: Ag), factor VIII coagulant activity (VIII: C) and tissue--type plasminogen activator antigen (t-PA:Ag). VO was less effective in increasing vWf: Ag and VIII:C but produced a greater rise in t-PA:Ag. Large increments (over 10-fold) were observed in plasmin-alpha 2-antiplasmin complexes following both stimuli. In vWd III (n = 10), DDAVP and VO failed to increase vWf:Ag, VIII:C and t-PA:Ag. No significant changes in plasmin-alpha 2-antiplasmin complexes were observed in this group. Moreover, the baseline t-PA:Ag values were significantly lower in vWd III (2.17 +/- 1.13 ng/ml) than in controls (4.84 +/- 1.97 ng/ml, p < 0.001). A significant increase in urokinase--type plasminogen activator antigen (u-PA:Ag) was found only in controls after VO. Neither controls nor patients with vWd showed any changes in plasma fibronectin levels following DDAVP. The low t-PA:Ag results and the abnormal fibrinolytic response to DDAVP and VO in patients with severe (type III) vWd indicate that their endothelial cell abnormality is more extensive than the defect in the synthesis or release of vWf.

Adult↗
PubMed1994

Granulocyte proteases and hydrogen peroxide synergistically inactivate thrombomodulin of endothelial cells in vitro.

Leukocytes release lysosomal proteases and reactive oxygen species in response to various stimuli that damage the adjacent endothelial cells. We investigated the effects of granulocyte lysosomal proteases (granulocyte elastase [GE] and cathepsin G [CG] and/or hydrogen peroxide (H2O2) on thrombomodulin (TM) activity of endothelial cells. We wished to determine whether the activated leukocytes damage the nonthrombogenic systems of endothelial cells. When cultured human umbilical vein endothelial cells (HUVECs) were incubated with GE, TM activity of the cells (as judged by the protein C activation capacity) decreased to about 10% of control with the concomitant increase of immunoreactive TM concentration in the conditioned media. CG also decreased TM activity to about 20% of control with the concomitant increase in immunoreactive TM concentration in the conditioned media. The GE- or CG-induced inactivation of TM was not observed in the presence of alpha 1-proteinase inhibitor. Immunoblot analysis showed that CG cleaved purified TM to yield one major fragment with an M(r) of 43,000; TM activity of this fragment was about 10% of the control activity. When purified TM was incubated with GE, TM activity decreased to 10% of control, and no detectable band was found on immunoblotting, suggesting that CG and GE cleave TM into inactive fragments and that GE degrades the epitope structure of TM. Although H2O2 (1.0 mmol/L) enhanced chromium 51 release from prelabeled HUVECs after 30 minutes of incubation, it decreased TM activity only slightly.(ABSTRACT TRUNCATED AT 250 WORDS)

Cathepsin G↗
PubMed1993

Organization of the gene encoding mouse vitronectin.

The gene (Vn) encoding the mouse vitronectin was isolated and its nucleotide sequence determined. The gene covers approximately 3 kb of genomic DNA. Alignment of the genomic sequence with that of the cDNA revealed that Vn consists of eight exons, interrupted by seven introns ranging in size from 78 to 723 bp.

Amino Acid Sequence↗
PubMed1993

Thrombin stimulates expression of tissue-type plasminogen activator and plasminogen activator inhibitor type 1 in cultured human vascular smooth muscle cells.

The effect of thrombin on the fibrinolytic potential of human vascular smooth muscle cells (SMC) in culture was studied. SMC of different origin responded to thrombin treatment with a dose and time dependent increase in tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor type-1 (PAI-1) levels in both cell lysates and conditioned media with maximum effects achieved at 10-20 IU/ml thrombin. PAI-1 antigen levels also increased in the extracellular matrix of thrombin treated SMC. PAI-2 levels in cell lysates of such SMC were not affected by thrombin. The effect was restricted to active thrombin, since DFP-thrombin and thrombin treated with hirudin showed no increasing effect on t-PA and PAI-1 levels in SMC. Enzymatically active thrombin also caused a four-fold increase in specific PAI-1 mRNA and a three-fold increase in t-PA mRNA. Furthermore we demonstrated the presence of high and low affinity binding sites for thrombin on the surface of SMC with a KD = 4.3 x 10(-10)M and 9.0 x 10(4) sites per cell and a KD = 0.6 x 10(-8) M and 5.8 x 10(5) sites per cell respectively. Thrombin could come in contact with SMC in case of vascular injury or following gap formation between endothelial cells. Our data support the idea that besides its known proliferative effect for SMC, thrombin could also modulate their fibrinolytic system.

Antigens↗
PubMed1993

Clinical value of determination of urokinase-type plasminogen activator antigen in plasma for detection of colorectal cancer: comparison with circulating tumor-associated antigens CA 19-9 and carcinoembryonic antigen.

We determined urokinase-type plasminogen activator antigen (u-PA), gastrointestinal cancer-associated antigen (CA 19-9), and carcinoembryonic antigen (CEA) in the plasma of patients with colorectal cancer at the time of clinical tumor detection and in a group of patients with Crohn's disease and analyzed the specificity of these tumor markers. u-PA, CA 19-9, and CEA were indicative for colorectal cancer in 75.5%, 51.5%, and 51.5% of tumor patients, respectively, with a specificity of 79.3%, 94%, and 97.5%. Sensitivity increased when two or all three markers were determined in identical blood samples, whereby a combination of u-PA and CEA exhibited the highest sensitivity value (90.9%) as compared to the combinations of u-PA and CA 19-9 or CA 19-9 and CEA. The use of all 3 markers did not lead to further increased sensitivity. False negative results were obtained in 3 of 32 cancer patients (9.1%, using one of 3 markers as indicative for malignant disease). These results indicate the benefit of multiparametric tumor marker analyses including u-PA antigen for the diagnosis of colorectal cancer.

Adult↗
PubMed1993

Type 1 plasminogen activator inhibitor synthesis of endothelial cells is downregulated by smooth muscle cells.

Plasminogen activator inhibitor type 1 (PAI-1), the physiologic inhibitor of both tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA), is a major biosynthetic product of endothelial cells in vitro; endothelial cells in vivo, in contrast, do not appear to produce significant amounts of PAI-1 as made evident by in situ-hybridization studies in normal mice. This suggests that the high rate of PAI-1 synthesis of endothelial cells in vitro might be a result of the culture conditions. When human umbilical vein endothelial cells (HUVEC) were grown on human amniotic membranes, resembling the natural growth support instead of coated plastic, their morphology was changed from the cobblestone-like appearance on plastic to an in vivo like flagstone pattern. However, this morphological change had no significant effect on the synthesis and secretion of PAI-1. When smooth muscle cell (SMC) conditioned media (CM) were added to HUVEC cultures, PAI-1 antigen secretion of HUVEC was reduced by 40% to 60% as measured by enzyme-linked immunosorbent assay (ELISA). Immunoprecipitation experiments using 36S-methionine metabolically labeled HUVEC and Northern blot analysis of HUVEC PAI-1 mRNA indicate that this reduction was attributable to decreased PAI-1 synthesis and reduced steady-state levels of both the 3.2 kb and 2.2 kb form of PAI-1 mRNA. This effect was dose-dependent and observed under serum-containing as well as serum-free conditions, in the absence or presence of endothelial cell growth supplement (ECGS, 0 to 100 micrograms/mL) and attributable to a nondialyzable factor. Our data suggest that the high level of PAI-1 biosynthesis of endothelial cells in vitro may be attributable to the lack of a soluble factor produced by SMC, which controls and suppresses PAI-1 biosynthesis of endothelial cells in vivo.

Cells, Cultured↗
PubMed1993

Influence of cardiac output on peak t-PA plasma levels in patients receiving thrombolytic therapy with recombinant tissue-type plasminogen activator--correlation with patency rate.

We studied 35 consecutive patients with short onset of myocardial infarction who underwent thrombolytic therapy with rt-PA at a standard dosage regimen of 100 mg rt-PA total (10 mg given as a bolus followed by 50 mg, 20 mg and 20 mg per hour for 3 hours). These patients were monitored for t-PA antigen and t-PA activity and PAI-1 activity plasma levels during rt-PA infusion. Success or failure of thrombolytic therapy was evaluated by non-invasive criteria (early plasma creatine kinase peaks, early peak plasma myoglobin values, and electrocardiographic criteria) as well as by means of coronary angiography at the fourth day after thrombolytic treatment. In 24 (68.6%) of these patients a success of thrombolytic therapy could be established by these criteria, while 11 patients did not respond to thrombolytic therapy. Fifteen patients (14 responders and one non-responder) had to be excluded from the further evaluation because in these patients clinical laboratory data obtained upon admission before initiation of thrombolytic therapy were not complete. Therefore, 20 patients (10 responders and 10 non-responders) could further be analysed. The two groups of patients were not significantly different in body weight, body weight index, age, gender, liver or kidney functional parameters as determined before initiation of the thrombolytic therapy. Furthermore, PAI-1 plasma levels before initiation of thrombolytic therapy were not significantly different in the two groups, as were rt-PA dosage per body weight or body weight index.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Factors contributing to increased vascular fibrinolytic activity in mongrel dogs.

BACKGROUND: Numerous investigators have observed that pulmonary emboli are rapidly lysed in a canine model system. This study was undertaken to delineate the unique mechanism that accounts for the rapid dissolution of pulmonary emboli in mongrel dogs. METHODS AND RESULTS: Canine plasminogen activator (PA) activity (2.6 +/- 1.1 IU/mL acidified platelet-poor plasma [PPP], < 0.3 IU/mL acidified whole blood serum [WBS], mean +/- SD; n = 6) and PA inhibitor activity (6.1 +/- 2.6 U/mL PPP, 35.4 +/- 7.8 U/mL WBS; n = 6) were determined in standard plasminogen-based chromogenic assays. Analysis of canine PPP, WBS, platelet lysates, and primary canine endothelial cell (EC) cultures by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fibrin autography revealed a plasminogen-dependent lytic zone at 45-kd relative molecular mass that was shown to be related to urokinase-type PA (u-PA) by its selective inhibition through amiloride. Analysis of canine platelets on standard 125I fibrin plate assays revealed a net fibrinolytic activity. In a clot lysis assay system, canine platelets were able to stimulate fibrinolysis when layered on the outside of fibrin clots containing autologous PPP. Moreover, net fibrinolytic activity of primary canine pulmonary artery endothelial cells was higher than the activities expressed by canine aortic or carotid artery endothelial cells. CONCLUSIONS: Rapid lysis of pulmonary emboli in mongrel dogs appears to be a result of 1) the high u-PA activity in canine PPP and 2) the predominant association of u-PA activity with canine platelets and canine pulmonary artery endothelial cells.

Animals↗
PubMed1993

The role of type-1 plasminogen activator inhibitor in failure of thrombolytic therapy with recombinant tissue plasminogen activator.

We investigated the possible role of type-1 plasminogen activator inhibitor (PAI-1) on success or failure of thrombolytic therapy with recombinant tissue plasminogen activator (rt-PA) in 10 responders and 10 non-responders with acute myocardial infarction and early initiation of therapy within 2 h of onset using the common infusion scheme (100 mg rt-PA over 3 h). We determined plasma levels of t-PA (activity and antigen) as well as PAI-1 (activity and antigen) in samples obtained before, during and after thrombolytic treatment and compared the course of each of those parameters between responders and non-responders to therapy. Success or failure of treatment was determined by a combination of noninvasive methods and proven by coronary angiography within 5 days of initiation of thrombolysis. Thirty, 60, 90, and 120 min after initiation of rt-PA infusion, specific t-PA activities in plasma of responders were 0.62, 0.63, 0.62, and 0.57 (IU/ng/ml), respectively, as compared to 0.42, 0.42, 0.40, and 0.32 (IU/ng/ml) in nonresponders (p < 0.001). Between 4 and 8 h after initiation of therapy, a time span known to be critical for thrombotic reocclusion, specific activities were still significantly elevated in responders as compared to non-responders (p < 0.01). PAI-1 activity levels, which were not detectable during rt-PA infusion in either group, recovered to pre-treatment values 2 h earlier in non-responders.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Vitronectin modulates glycosaminoglycan dependent reactions of protein C inhibitor.

Protein C inhibitor (PCI), a glycosaminoglycan (GAG) dependent serine protease inhibitor, inhibits its target proteases by forming SDS-stable 1:1 complexes. GAGs alter target enzyme specificity of PCI in such a way that e.g. urokinase (uPA) is the preferred target enzyme in the presence of GAGs while in their absence preferentially tissue kallikrein (TK) complexes are formed. The effect of the GAG-binding adhesive glycoprotein vitronectin (Vn) on the GAG-stimulated inhibition of uPA by PCI was studied using an amidolytic assay. In the presence of heparin, Vn protected uPA from inhibition by PCI in a dose-dependent manner with respect to both, Vn- and heparin-concentration. Vn also was active when heparin was replaced by low-molecular weight heparin or heparan sulfate, respectively. In the absence of GAGs, Vn had no effect on the inhibition of uPA by PCI. In a similar system, Vn was far less effective in modifying the inhibitory function of heparin on the inhibition of TK by PCI. When equimolar concentrations of radiolabelled uPA and TK were incubated with PCI in the presence of heparin, only complexes of PCI with uPA were detectable. Addition of Vn reduced this complex formation, whereas, in contrast, complexes of PCI and TK appeared. These results indicate that Vn modulates both, the activity and specificity of PCI and suggest different structural heparin-requirements for the PCI/uPA versus PCI/TK interaction.

Amides↗
PubMed1992

Polar secretion of endothelin-1 by cultured endothelial cells.

The aim of this study was to determine the permeability of endothelial monolayers for endothelin-1 and a possible directionality of the endothelin-1 secretion process. Human umbilical vein endothelial cells were cultured on acellular amniotic membranes, dividing the tissue culture wells into an apical (luminal) and a basolateral (abluminal) compartment. Whereas in the absence of endothelial monolayers 44.9 +/- 2.3 and 43.5 +/- 2.0% of the unilaterally added endothelin-1 permeated from the apical to the basolateral side and from the basolateral to the apical side, respectively, only 6.5 +/- 0.6 and 6.6 +/- 0.4% diffused in the presence of endothelial cells. Analyzing endothelin-1 secretion, approximately 80% of the total amount of synthesized endothelin-1 was found in the basolateral compartment; thrombin (10 units/ml) stimulated the production of endothelin-1 approximately 2-fold, but did not change the relative distribution of endothelin-1 between the apical and basolateral compartments. In the presence of dexamethasone (10(-7) M), a decrease in the level of endothelin-1 was found in the apical compartment, whereas the total amount of endothelin-1 produced was not affected. Dexamethasone did not influence the permeability of human umbilical vein endothelial cell monolayers for endothelin-1. These results strongly support the hypothesis that endothelin-1 is a local paracrine regulator of vasotone.

Amnion↗
PubMed1992

Direct evidence for systemic fibrinogenolysis in a patient with metastatic prostatic cancer.

Although the possible occurrence of systemic fibrinogenolysis has been suggested in patients with metastasising prostatic cancer (MPC), direct evidence is lacking. We report on a patient with MPC whose laboratory data were consistent with hyperfibrinolysis: marked decrease of alpha 2-antiplasmin (AP) level (less than 50% of normal), increase of plasmin-alpha 2-antiplasmin complex, D-fragment of fibrin and fibrinogen degradation products [FDP(D)] and cross-linked fibrin degradation products (XDP). The patient neither showed laboratory nor clinical evidence for consumption coagulopathy except for a slight increase in thrombin-antithrombin III complex level. Immunoblotting of the patient's serum using an anti-fibrinogen antibody revealed the presence of a 250 kDa protein in addition to DD fragments. Following reduction of this protein by 2-mercaptoethanol after extraction from SDS-PAGE gel, gamma-chain of fibrinogen (47 kDa) was found by immunoblotting using a monoclonal antibody recognising a 86-302 residue of the gamma-remnant of fibrinogen. Moreover, the 250 kDa protein did not bind to Sepharose 4B to which a monoclonal antibody recognising the N-terminus of fragment D was conjugated. These findings indicated that this protein was not fragment DY, but rather fibrinogen fragment X. With the retraction of the prostatic tumour by an effective therapy, the patient's AP level increased gradually. When the plasma AP level rose to 60% of normal, the fragment X was no longer detectable. These findings suggested that systemic fibrinogenolysis occurred in the patient with MPC only when AP levels were markedly decreased.

Aged↗
PubMed1992

Modulation of heparin cofactor II activity by glycosaminoglycans and adhesive glycoproteins.

Heparin cofactor II (HCII) is a specific thrombin inhibitor; its inhibitory activity is stimulated by heparin (Hep) and dermatan sulfate (DS). Vitronectin (VN), a heparin binding adhesive glycoprotein present in plasma and extracellular matrix, has been shown to decrease the stimulatory effect of Hep but not of DS on thrombin inhibition by HCII (Preissner and Sié, 1988). We analyzed the effect of glycosaminoglycans (GAGs) and GAG-binding proteins on the HCII/thrombin interaction in more detail. HCII was purified from the supernatant of barium citrate adsorbed normal human plasma by polyethylene glycol precipitation followed by affinity chromatography on heparin-Sepharose CL-6B and ion-exchange chromatography on a QAE-Sephadex A-50. Inhibition of thrombin by HCII was studied in the absence and presence of GAGs (hep 0.03-30 micrograms/ml, DS 0.05-50 micrograms/ml, heparan sulfate (HS) 0.05-50 micrograms/ml) in a chromogenic substrate assay using S-2366 as a thrombin substrate. The effects of VN and fibronectin (FN) on HCII stimulation by GAGs were determined. In addition to Hep and DS the inhibitory effect of HCII was stimulated by HS, however, to a lesser extent. Using 0.03U/ml thrombin and 1nM HCII the stimulatory effect of GAGs was completely inhibited when Hep (less than or equal to 0.3 micrograms/ml) was preincubated with VN (60 micrograms/ml) and decreased to less than 50% when HS (50 micrograms/ml) was preincubated with VN (60 micrograms/ml). VN had no effect on DS as already described previously.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Adhesion↗
PubMed1992

Endogenous receptor-bound urokinase mediates tissue invasion of the human lung carcinoma cell lines A549 and Calu-1.

Macrophage colony-stimulating factor (CSF-1) increases the tissue invasive potential of the CSF-1 receptor-bearing lung carcinoma cell lines A549 and Calu-1 by increasing the number of endogenously bound urokinase-type plasminogen activators (u-PA)s on these cells. CSF-1, at concentrations which optimize invasion of A549 and Calu-1 cells into human amnion membranes (250 ng/ml), maximally augments the number of u-PA receptors occupied by endogenously produced urokinase. Preincubation of A549 and Calu-1 cells with the anti-u-PA monoclonal antibody MPW5UK (25 micrograms/ml) or with a 20- to 40-fold stoichiometric excess of fluid phase type 2 plasminogen activator inhibitor abrogates invasiveness, indicating that functionally active cell surface u-PA is essential for tissue invasion. In contrast, fluid phase type 1 plasminogen activator inhibitor (PAI-1, 5-15 units/ml) does not inhibit invasiveness unless preincubated with the amnion membranes. Inhibition of invasion by PAI-1 is abolished by presaturating the amnion membranes with antiitronectin monoclonal antibody (10 micrograms/ml) which prevents binding of PAI-1 to tissue-associated vitronectin. Binding of PAI-1 to tissue vitronectin is therefore a prerequisite for its inhibitory action. Thus, endogenously receptor-bound u-PA is the primary protease mediating CSF-1-induced tissue invasiveness of the lung carcinoma cell lines A549 and Calu-1.

Amnion↗