Vasospastic angina caused by 5-fluorouracil. A case report.
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Biomedical subjects
Publications and source records attributed to R Vlaicu.
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This study describes the relationship between nitroglycerin, isosorbide dinitrate, sodium nitroprusside, and carbonic anhydrase I, as well as the involvement of this carbonic anhydrase I in vasodilation. Two groups of coronary patients and a group of rabbits underwent treatment with the above-mentioned vasodilating drugs. The activity of red blood cell carbonic anhydrase was monitored and determined by the stopped-flow method. The results show that these drugs inhibit the activity of the isozyme in parallel to their vasodilating effect. The results of this study lead to the hypothesis that through the pH modifications induced by these vasodilators by the inhibition of carbonic anhydrase I, the isozyme may be involved in the regulation of vascular tonus.
Interleukin 6 (IL-6) and interleukin 8 (IL-8) are present in the human arterial atherosclerotic wall as cellular and extracellular deposits in the connective tissue matrix. Quantitative determinations of IL-6 by ELISA showed mean values of 27.6 +/- 3.3 ng/100 mg protein in normal intima, 37.3 +/- 2.1 ng/100 mg protein in fibrous plaque and 25.7 +/- 4.3 ng/100 mg total extracted protein in media. IL-8 levels were 3.5 +/- 0.6 ng/100 mg protein in normal intima, 11.3 +/- 2.1 ng/100 mg protein in fibrous plaque and 8.5 +/- 1.4 ng/100 mg total extracted protein in media. Fibrous plaques presented statistically significant higher levels of both IL-6 and IL-8. IL-6 and IL-8 gene transcripts were present in human iliac fibrous plaque and media prelevated at surgery indicating that a local production by the cells of the arterial wall participate to their accumulation. We also tested the role of complement activation in induction of IL-6 and IL-8 protein synthesis as well as the subsequent activation of endothelial cells. Only IL-8 was induced by complement activation and this may contribute to increased IL-8 levels found in the atherosclerotic wall. When exposed to terminal complement complexes, endothelial cells in culture also showed an increase of both DNA-synthesis and p70 S6 kinase activity indicating that complement is able to induce not only IL-8 synthesis but also cell activation. The presence of IL-6 and IL-8 in the arterial wall where complement activation also occurred, clearly show the involvement of inflammatory events in initiation and progression of atherosclerosis.
The neoantigens of the C5b-9 complement complex, IgG, C3, C4, S-protein/vitronectin, fibronectin, and macrophages were localized on 17 samples of breast cancer and on 6 samples of benign breast tumors using polyclonal or monoclonal antibodies and the streptavidin-biotin-peroxidase technique. All the tissue samples with carcinoma in each the TNM stages presented C5b-9 deposits on the membranes of tumor cells, thin granules on cell remnants, and diffuse deposits in the necrotic areas. When chemotherapy and radiation therapy preceded surgery, C5b-9 deposits were more intense and extended. The C5b-9 deposits were absent in all the samples with benign lesions. S-protein/vitronectin was present as fibrillar deposits in the connective tissue matrix and as diffuse deposits around the tumor cells, less intense and extended than fibronectin. IgG, C3, and C4 deposits were present only in carcinoma samples. The presence of C5b-9 deposits is indicative of complement activation and its subsequent pathogenetic effects in breast cancer.
Tumor necrosis factor-alpha (TNF-alpha) was demonstrated in human normal and atherosclerotic aorta, iliac and femoral arteries by immunohistochemistry using monoclonal and polyclonal antibodies. TNF was present in the cells of the arterial wall and as granular and diffuse extracellular deposits in the connective tissue matrix. Quantitative determinations of TNF by ELISA showed mean values of 21.7 +/- 0.7 ng/100 mg total extracted protein in normal intima, 38.2 +/- 0.5 in intimal thickenings, 25.5 +/- 1.1 in fibrous plaques and 16.8 +/- 0.2 ng/100 mg total extracted protein in media. Intimal thickenings presented the highest amounts of TNF with a statistically significant difference when compared to normal intima (P less than 0.05) and media (P less than 0.01). TNF-alpha concentrations in arterial eluates were about 200 times higher than in the corresponding serum samples. Western blotting analysis confirmed TNF-alpha eluted from the arterial wall to be about 17 kDa similar to human recombinant TNF-alpha. TNF-alpha in human atherosclerotic wall could be actively involved in the inflammatory events associated with atherosclerosis.
The study included 62 patients with atherosclerosis obliterans of the lower extremities, of whom 47 in stage II, 5 in stage III and 10 in stage IV of the disease. In 22 patients were present single arterial obliteration, in 30 patients multiple, layered arterial obliterations, in 8 distal arterial obliterations and 2 a diffuse atherosclerosis of the lower extremities. Patients were examined in admission to the clinic, after the treatment performed at the clinic and at various intervals, during 2-4 years. The segmental arterial pressure, the pressure index and the ultrasonogram recorded with the Cardior electrocardiograph were followed-up. The arterial pressure and the pressure indices returned to normal values only after invasive procedures. The medical treatment can bring about the clinical regression and stabilization of the disease, as well as the improvement of the ultrasonogram. For the choice of therapeutic means, the pressure index is the best criterion, since it correlates with the severity of the disease. In the case of a pressure index 0.75, the medical treatment or the transluminal dilatation is preferred, whereas at an index of 0.7 the surgical revascularisation is considered necessary. Other ultrasonic parameters were also taken into account, such as the systolic passage time and the maximum velocity, which are less important in the attainment of the mentioned aims.(ABSTRACT TRUNCATED AT 250 WORDS)
Decay-accelerating factor (DAF) is an intrinsic membrane inhibitor that regulates the activity of C3 and C5 convertases of the classical and alternative complement pathways. Using two monoclonal antibodies, IC6 and IA10, DAF was localized by immunohistochemistry using streptavidin-biotin-peroxidase complex or silver-intensified immunogold techniques in aortic, iliac and femoral samples obtained at surgery and autopsy from 32 patients. DAF was localized on the cells and in the connective tissue matrix of the arterial wall. Fibrous plaques and intimal thickenings presented larger amounts than fatty streaks, intimae and normal areas. By Western blotting analysis, DAF extracted from the arterial wall had a molecular weight of about 67 kDa. Using a double-labeling technique, DAF and C5b-9 complexes were co-localized on nucleated cells and on cell debris. The cells isolated after enzyme digestion of the arterial wall were tested for the protective role of DAF to complement-mediated damage. When DAF of the sensitized cells was blocked by monoclonal antibodies, complement-mediated cell lysis was enhanced from 10-15% to 60-70%. The effect of anti-DAF antibodies was dose-dependent. DAF blocking in the absence of antibodies used for sensitization led to a lysis under 10%. These data suggest a protective role of DAF against autologous complement activation, however insufficient to prevent complement activation in the human atherosclerotic wall.
The serum concentration of Zn and Cu were determined in 126 controls and 160 patients with atherosclerosis obliterans (AO) and 53 patients with thromboangiitis obliterans (TO). The concentration of serum Zn decreases with age both in controls and patients with AO in all the evolutive stages of the disease. In patients with TO, the concentration of serum Zn shows no correlation with age. The significantly lower values of serum Zn in controls and patients with AO over 61 yr than those below this age is attributed to the decreased Zn supply, especially to some individual cellular abnormalities. The values of serum Cu are higher in patients with AO and TO than in controls irrespective of the evolutive stage of the disease. This was related to cigarette smoking and inflammation. The Zn/Cu ratio in the serum is below 1 in patients with AO and TO and in controls over 61-yr-old. The pathogenetic role of this ratio in atherosclerosis and inflammation still remains a controversial question.
S-protein/vitronectin is a multifunctional glycoprotein interacting with both complement activation and coagulation pathways. Its presence was investigated in 5 femoral and 5 iliac atherosclerotic human arteries, obtained at surgery, by immunoelectron microscopy using an affinity purified rabbit IgG specific for human S-protein/vitronectin. The immunoelectron dense specific deposits were found in both intimal thickenings and fibrous plaques in association with elastic fibers, collagen bundles and cell debris in the vicinity of elastin. Cell debris embedded in the collagen matrix were S-protein/vitronectin negative. S-protein/vitronectin was also absent on intact cells, lipid droplets and cholesterol clefts. All cell debris, however, was positive for C5b-9 deposits suggesting that complement activation had occurred at these sites with or without S-protein/vitronectin interaction. S-protein/vitronectin may play a role in the arterial wall defence by restricting the extent of complement activation.
Fibrous plaques and intimal thickenings of 5 femoral and 5 iliac human arteries obtained at surgery were processed for indirect and double-labeling immunoelectron microscopy using an affinity purified rabbit IgG anti-C5b-9 neoantigen and the EBM 11 monoclonal antibody anti-human macrophages. The C5b-9 complexes were localized in intact cells, disintegrated cells and cell debris enmeshed in the connective tissue matrix. Some of the cell debris bearing C5b-9 deposits was found to be of macrophage origin. Endocyted or exocyted pieces of membrane with pore-forming C5b-9 complexes were also identified. Damage of cells by complement in atherosclerotic lesions may contribute to atherogenesis.
The absolute and relative bioavailability of nifedipine (1) from different formulations administered as single oral doses in healthy volunteers was determined. Serum concentrations of 1 were measured by GC. The absolute bioavailability of 1 was 53% because of presystemic metabolism. The bioavailability of Adalat (Bayer) tablets, Nifedipina (Terapia) and Corinfar (VEB Arzneimittelwerk Dresden) sugar-coated tablets was 93%, 92% and 86% (respectively) as compared with Adalat capsules. The AUC were not significantly different. The Cmax and tmax values were different, indicating that the absorption of 1 showed differences in first-order rate constants of dissolution in the above mentioned order. Despite the differences among the formulations studied, each preparation may have its merits. In a multiple dose regimen of 20 mg 1 (Nifedipina, Terapia) t.i.d., minimal therapeutic drug levels were achieved and maintained during steady state, from the 1st d of treatment.
The relationship between macrophages and the terminal C5b-9 complement complexes was investigated in human arteries affected with atherosclerosis by using monoclonal antibodies and indirect immunoperoxidase, immunogold silver staining, and double-labeling immunohistochemical techniques. Macrophages were found in all the atherosclerotic arteries as immunoreactive deposits with a nucleus, considered as intact cells, or without a nucleus, considered as cell remnants. The double-labeling technique shows C5b-9 deposits partially colocalized on the intact macrophages or on the cell debris of macrophage origin. These data suggest that C5b-9 complement complex may be formed on activated or dying macrophages with subsequent promotion of inflammatory events and progression of the atherosclerotic lesions.
The co-localization of terminal C5b-9 complement complexes and macrophages was investigated in human arteries with atherosclerosis using a double-labeling immunohistochemical technique. Macrophages were found in all the atherosclerotic arteries, with the accumulation correlating positively with the degree of atherosclerosis. This accumulation was associated with an increase of C5b-9 deposits, as well as with an increase in the number of deposits containing both complement components and macrophages ('co-localization'). This co-localization was found to pertain both to intact macrophages and to macrophage remnants. These data suggest that C5b-9 complement complex might be formed on macrophages with subsequent promotion of inflammatory events and progression of the atherosclerotic lesions.
The terminal C5b-9 neoantigens of the complement complex, S-protein (Vitronectin), C3c, C3d and apolipoprotein B were localized on 16 aortic fibrous plaques, 8 aortic intimal thickenings, 4 fatty streaks intimae, 12 coronary fibrous plaques, 3 coronary intimal thickenings, 6 femoral and 5 basilar fibrous plaques, using an indirect and double-staining immunoperoxidase method. The granular specific deposits were localized in the fibrous cap and deeper parts of the plaque or in the deeper intima and inner-third media of intimal thickenings and fatty streaks intimae, in relation to the degree of atherosclerotic involvement. The different localization of C5b-9 and S-protein demonstrated by the double-staining technique is more suggestive for the assembly of the complex into the arterial wall and not for its preformed passage from circulation. The relation of these immune deposits to the degree of fibrosis and necrosis and their presence from the initial stages through to the advanced lesions could ascribe a role to the complement system in atherosclerosis.
The presence of the terminal C5b-9 complement complex in tissues indicates that complement activation has occurred in situ with subsequent membrane damage, tissue injury, and inflammatory response mediation. The terminal C5b-9 neoantigens of the complement system, S protein C3c, C3d, and apolipoprotein B deposits were localized in 20 aortic fibrous plaques, 12 aortic intimal thickenings, 8 aortic fatty streak intimae, 14 coronary fibrous plaques, 5 coronary intimal thickenings, and 8 femoral fibrous plaques, using an indirect and double-staining immunoperoxidase technique. The specific granular deposits were present from the early to the advanced stages of atherosclerosis in relation to the degree of fibrosis and necrosis. The different double-staining localization of C5b-9 and S protein may suggest local assembly of the complex as a consequence of complement activation and may sustain its role in the chronic progression of atherosclerosis.
Myocardial fragments with acute infarction (10 cases), scars after chronic infarction (6 cases), areas with focal sclerosis and necrosis (8 cases) compared with normal myocardial areas (8 cases), were processed for indirect and double-labelling immunoperoxidase techniques to localize C5b-9 neoantigens, S-protein, C3d and apolipoprotein B. Granular masses of C5b-9 and C3d and diffuse areas of S-protein and apolipoprotein B were localized in the acute or chronically damaged areas but not in areas free of lesion. Double-labelling data revealed similarly damaged areas of localization for C5b-9 and S-protein, and for C3d and apolipoprotein B, respectively, on rather different than usual tissue structures. C5b-9 determination by ELISA from myocardial eluates revealed lower levels of neoantigens in normal areas (2.3 +/- 0.3 micrograms/g dried tissue), higher levels in areas with sclerosis (7.9 +/- 0.7 micrograms/g dried tissue) and the highest amounts in areas with acute infarction (11.1 +/- 1.2 micrograms/g dried tissue). The presence of C5b-9 neoantigens in damaged myocardial areas with a different localization than S-protein is suggestive of local complement activation.
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A quantitative ELISA using monoclonal and polyclonal antibodies against neoantigens of the terminal C5b-9 complement complex was used to evaluate the presence of terminal complexes in 68 human arterial samples with or without atherosclerotic involvement. Plasma levels of SC5b-9 were directly compared with the corresponding levels eluted from the femoral arteries in six patients undergoing surgical procedures. The plasma concentration of SC5b-9 in these donors was in the range of 30-90 arbitrary units (AU)/ml, equivalent to 100-300 ng/ml SC5b-9 or 45-130 AU/100 mg plasma protein. All the arterial samples contained detectable amounts of C5b-9. The aortic normal and fatty streaks intimae presented a minimum mean value of 65 +/- 12 AU/100 mg total protein, in the range of normal plasma SC5b-9 levels. The corresponding media contained significantly higher amounts of terminal complexes (115 +/- 30 AU/100 mg protein). Markedly increased levels of C5b-9 were eluted from aortic intimal thickenings (350 +/- 100 AU/100 mg protein) and the corresponding media (300 +/- 53 AU/100 mg protein). Similar concentrations were found in aortic fibrous plaques (340 +/- 80 AU/100 mg protein). The observed correlation between C5b-9 levels and atherosclerotic alterations in arterial walls is suggestive of chronic complement activation with involvement of the terminal complement sequence at these sites. These processes may contribute to progression of the arteriosclerotic lesions.