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Results 651 - 700 of 775
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de Ricqlès D - - 1993
We have previously reported that breast cancer patients and some healthy subjects show positive T-cell-mediated immune responses to a semi-purified mouse mammary tumour viral pool (MMTV). We have now used Western blotting to analyse the specificity of the response and to determine the target polypeptides. Two types of T-cell response ...
Skarlatos S I - - 1993
Lipoprotein lipase, a lipolytic enzyme essential for normal hydrolysis of triglycerides in very low density lipoprotein (VLDL) and chylomicrons, is found in several cell types, including macrophages. The role of lipoprotein lipase in mediating the uptake of normal VLDL triglycerides into human cultured monocyte-derived macrophages was studied using macrophage cells ...
Yui S - - 1993
We previously reported that cell membrane components and lipoproteins were able to induce the growth of murine peritoneal macrophages. The aim of the present study was to examine whether macrophage growth could also be induced by chemically modified lipoproteins, such as acetylated low density lipoprotein (acetyl-LDL) or oxidized LDL, ligands ...
Schwartz C J - - 1993
Two key events in the atherogenic cascade are the focal influx and accumulation of low-density lipoprotein (LDL) cholesterol at arterial sites having a predilection for atherosclerotic lesion development and the recruitment of blood monocytes to these lesion-prone sites. Both processes are enhanced in the setting of hyperlipidemia and dyslipoproteinemia. The ...
Aviram M - - 1993
Modified forms of low density lipoprotein (LDL) are associated with increased atherogenicity. Modified LDL, in comparison with native LDL, demonstrates enhanced cellular uptake by macrophages, foam cell formation and also causes the secretion of cytokines and growth factors from arterial wall cells. Non-enzymatic modifications of LDL (proteoglycans, glycosylation, immune complexes) ...
Blocki F A - - 1992
Mammals have separate enzymatic and cellularly mediated detoxification systems. Glutathione S-transferases (GSTs) protect against xenobiotic chemicals which continuously enter the body, largely through mucous membranes. These enzymes catalyse the conjugation of glutathione with a wide variety of electrophilic compounds rendering them non-toxic. Mammals also mount a cellular immunological response on ...
Lopes-Virella M F - - 1992
It was recently proposed that the increased levels of modified lipoproteins in diabetic patients may be responsible for the accelerated development of macrovascular complications associated with the disease. Modified lipoproteins are believed to induce the transformation of macrophages into foam cells and, in some cases, to induce endothelial cell damage. ...
Yates M T - - 1992
Low density lipoproteins (LDL) oxidatively modified by macrophages have been shown to be atherogenic in ex vivo studies. We studied the potential role of nitric oxide (NO), a free radical produced by macrophages, in LDL modification. Human LDL (1 mg/ml) were incubated with mouse peritoneal macrophages in Ham's F-10 medium. ...
Roma P - - 1992
In J774 murine macrophages, chemically oxidized LDL (OxLDL) and biologically oxidized LDL (BioOxLDL) have similar metabolic fates, characterized by a relatively poor degradation when compared with acetylated LDL (AcLDL), and a modest ability to activate acyl-CoA:cholesterol acyltransferase (ACAT) (850 and 754 pmol [14C]oleate/mg cell protein in OxLDL- and BioOxLDL-incubated cells, ...
Oiknine J - - 1992
Inflammation is associated with macrophage activation, and this process has been shown to occur during atherogenesis. Macrophages (J774A.1) that were activated with either lipopolysaccharide (LPS), zymosan, or phorbol ester demonstrated a 30-35% increased uptake and degradation of low density lipoprotein (LDL) in comparison with nonactivated cells. This phenomenon was also ...
Grove R I - - 1991
Recent evidence suggests the possibility that macrophages can influence lipoprotein metabolism. Therefore we investigated the ability of cultured macrophages to alter low density lipoprotein (LDL) uptake in a human liver cell line (HepG2). Conditioned media from phlogogenic-induced mouse peritoneal macrophages or from a human macrophage cell line stimulated with endotoxin ...
Horváth M - - 1991
The immunomodulatory effect of the lipid-reducing etofibrate, the calcium antagonist nifedipine and the immunosuppressive cyclosporine A was studied on in vitro cellular immune response in the presence of human aortic extract and of human LDL in 56 patients with acute myocardial infarction. 50 sex- and age-matched healthy persons were used ...
Grunfeld C - - 1991
The hypertriglyceridemia of infection is produced by many of the cytokines that regulate the immune response, including the tumor necrosis factors, interleukin-1, interleukin-6, and the interferons. In rodents, this hypertriglyceridemia is primarily due to the ability of these cytokines to stimulate hepatic lipogenesis and very low density lipoprotein production without ...
Griffin H - - 1991
The results of the present study strongly suggest that the hypertriglyceridaemia in chicks treated with Aroclor 1254 is a result of reduction in VLDL clearance rather than an increase in rate of VLDL secretion. The decrease in post-heparin LPL activity responsible for reduced VLDL clearance may be mediated by cytokines ...
Mehta U - - 1991
The present study was addressed to understand two specific issues: (a) whether atherogenic activity of smooth muscle cells could be initiated by incorporating cholesterol within their membranes through a LDL-receptor-independent pathway; and (b) whether trifluoperazine, which we had recently shown to prevent the cholesterol-induced atherogenesis in an experimental animal model ...
Devi R S - - 1991
Rats with bilateral electrolytic ventral hippocampal formation (VHF) lesion show a significantly (p less than 0.001) enhanced migration of leucocytes in the presence of antigen. Immunization in these animals enhances (p less than 0.001) the leucocyte migration and presents a significant decrease in footpad thickness. Antibody titre (p less than ...
Nigon F - - 1991
We have evaluated the effect of native low-density lipoproteins (LDL) on the production of leukotriene B4 (LTB4), a potent inflammatory and chemotactic factor, by human monocyte-derived macrophages. The capacity of LDL (d, 1.024-1.050 g/ml) to increase LTB4 secretion was dose-dependent with an optimal response at 100 micrograms LDL protein/ml, representing ...
Gisinger C - - 1991
We have recently shown that incubation of macrophages with insoluble immune complexes (IC) containing low-density lipoproteins (LDL) leads to intracellular accumulation of esterified cholesterol (CE). This accumulation is associated with morphological transformation of the macrophages into "foam cells." In order to better characterize the conditions that lead to the uptake ...
Rankin S M - - 1991
It has been suggested that the oxidative modification of low density lipoprotein (LDL) is a key event in atherogenesis. Several mechanisms have been proposed to explain how different types of cells modify LDL. In this study we examine the relative contributions of superoxide anions and cellular lipoxygenase (LO) in the ...
Srinivasan S R - - 1991
The arterial wall proteoglycans play a crucial role in the pathogenesis of atherosclerosis as depicted schematically in Figure 7. Plasma components including lipoproteins cross the endothelium mainly by a non-specific bulk-phase vesicular transport. A selective interaction of apoB-containing lipoproteins occurs with proteoglycans of the subendothelial layer which results in extracellular ...
Goldberg A - - 1991
Cellular responses in bee venom (BV) allergy is a controversial issue. Previous studies could not reach an agreement whether this mechanism is activated as a result of allergic sensitization to bee venom. All previous works have used lymphocyte proliferation as their method to analyze cell-mediated immunity. In the present work, ...
Saini J S - - 1990
Varied manifestations of herpes simplex keratitis are postulated to be related to alterations or paucity of protective immune response to the virus. In this study lymphocyte subpopulations and macrophage inhibition factor (MIF) assay are investigated in herpes simplex keratitis. Active T-lymphocytes are detected to be significantly low in active keratitis ...
Fong L G - - 1990
In vitro, metabolism of modified forms of low density lipoprotein (LDL) by macrophages via the acetyl-LDL receptor pathway promotes the massive cellular accumulation of lipid. It has been postulated that in vivo this contributes to foam cell formation in the atherosclerotic lesion. Recent studies have shown that arterial wall cells ...
Cavaillon J M - - 1990
Recent evidence suggests that bacterial lipopolysaccharide binds to serum lipoproteins in vitro and in vivo and that lipopolysaccharide in the form that is bound to lipoprotein is less biologically active in several experimental models. In order to study the mechanism of this apparent detoxification, we compared the ability of free ...
Tertov V V - - 1990
Blood serum of most patients with coronary heart disease (CHD) caused a 2- to 5-fold increase in the lipid content of smooth muscle cells cultured from unaffected human aortic intima, i.e., possessed an atherogenic potential manifested in culture. Treatment of the CHD patients' serum with 2.5% polyethylene glycol 6000 removed ...
Ishibashi S - - 1990
We investigated the roles of lipoprotein lipase and apolipoprotein E (apoE) secreted from human monocyte-derived macrophages in the uptake of very low density lipoproteins (VLDL). ApoCII-deficient VLDL were isolated from a patient with apoCII deficiency. The lipolytic conversion to higher density and the degradation of the apoCII-deficient VLDL by macrophages ...
Faust R A - - 1990
Human macrophages in vitro synthesize and secrete the cholesteryl ester (CE) transfer protein, LTP-I. The effect of differentiation of monocyte-to-macrophage on the synthesis and secretion of LTP-I cholesteryl ester transfer activity was investigated. One marker of macrophage differentiation is expression of the 'scavenger' receptor, which mediates macrophage uptake and degradation ...
Frostegård J - - 1990
Hypercholesterolemia is a major risk factor for development of atherosclerosis. In experimental animals fed a high-cholesterol diet, monocytes adhere to the arterial endothelium and penetrate into the intima where they differentiate into macrophages and ingest lipids thus giving rise to fatty streaks, the earliest type of atherosclerotic plaque. Macrophages express ...
Kraemer F B - - 1990
The effects of activation on lipid and lipoprotein metabolism were examined in resident murine macrophages, inflammatory cells elicited by thioglycolate, primed cells elicited by pyran copolymer, and activated cells elicited by Corynebacterium parvum. Low density lipoprotein receptors were reduced by 70%, while scavenger receptors were reduced 60% in activated cells. ...
Singh S - - 1990
Candida albicans was found to repeatedly colonise and invade the duodenal ulcer base in a 45 years old otherwise healthy patient receiving H2 receptor antagonists for a prolonged period. He had no delayed hypersensitivity to Candida skin test, and had T cell deficiency, abnormality in T cell blast transformation, defective ...
Schwartz C J - - 1989
Atherosclerosis is conceptually defined as the result of a multiplicity of interactive cascades among injurious stimuli and the healing responses of the arterial wall, occurring concurrently within a hyperlipidemic environment. In this discussion, the inflammatory nature of the disease is emphasized. Four aspects of the pathophysiology of atherogenesis are addressed: ...
Khoo J C - - 1989
It was previously reported by Tabas et al. that J774 macrophages, unlike mouse peritoneal macrophages, accumulate large amounts of cholesteryl esters when incubated with native low-density lipoprotein (LDL). Comparison of the cell line (designated J774A.2) used in those experiments with its parent line (J774A.1) indicates that it is a variant ...
Rasmussen L T - - 1989
Human peritoneal macrophages were stimulated in vitro with beta-1,3-D-polyglucose-derivatized microbeads (GDM) or soluble aminated beta-1,3-D-polyglucose (AG) in combination with lipoproteins. The release of interleukin 1 (IL-1) was analysed in cell supernatants in a thymocyte proliferation assay. We report that the release of IL-1 is markedly enhanced in macrophages stimulated with ...
Simon M - - 1989
Synthesis of the Epstein-Barr virus (EBV) associated early antigen (EA) can be induced by a variety of agents in Raji cells, a latently EBV-infected Burkitt lymphoma line. We investigated the role of lipoproteins in this EA induction system. Cell growth was not affected by lipoprotein-deficiency, but EA induction by most ...
Gillissen G - - 1988
Antibiotics may influence immune response by quite different ways. By screening the multitude of publications on this subject, the aim of this overview was to arrive at a basic generalizing statement on the relationship between chemical structure or mode of action of antibiotics and the effect on immune response and ...
Griffith R L - - 1988
Human macrophages play a key role in atherogenesis and are believed to be the progenitors of the cholesteryl ester (CE)-laden foam cells present in early atherosclerotic lesions. Several mechanisms by which macrophages accumulate CE have been recently described. One involves a perturbation in LDL metabolism subsequent to macrophage activation. Thus, ...
Aviram M - - 1988
Cholesterol-loaded human monocyte derived macrophages secrete distinct class of lipoprotein. Following macrophages incubation in serum-free medium containing [14C]-oleic acid the cells secrete lipoprotein associated radioactivity that was found in triglycerides, phospholipids and cholesteryl ester. Macrophage lipoprotein secretion was analyzed by non-denatured gradient gel electrophoresis, agarose lipoprotein electrophoresis and discontinuous density ...
Steinberg D - - 1988
Previous studies from this laboratory have shown that oxidative modification of low-density lipoprotein (LDL) causes it to be recognized by the scavenger receptor of the macrophage. Consequently, the rate of degradation of oxidized LDL by macrophages can be 3 to 10 times that of native LDL. Antioxidants, such as probucol, ...
Falcone D J - - 1988
The ability of acetyl-LDL to stimulate macrophage-dependent plasminogen activation and degradation of extracellular matrix was examined. We have found that expression of plasminogen activator activity in response to the scavenger receptor ligand varied among cell populations. Exposure to acetyl-LDL stimulated plasminogen activator expression by cells which constitutively released low levels ...
Zwadlo G - - 1988
Using a monoclonal antibody to macrophage migration inhibition factor (MIF), two proteins were isolated from supernatants of Concanavalin A-stimulated human peripheral blood mononuclear cells which seem to have complexed to a third component carrying the MIF activity. They are therefore designated MIF-related proteins or MRP-8 and MRP-14 according to their ...
Miyagawa N - - 1988
The effect of human C-reactive protein (CRP) isolated and purified from pooled patients' sera on macrophage function, especially on macrophage migration, was studied. Peritoneal exudate cells (PEC) from guinea pigs were used for macrophage migration inhibition (MMI) test of capillary method. Migration of either PEC or adherent purified macrophages exposed ...
Massmann J - - 1988
Interendothelial and subendothelial monocytes/macrophages are extremely rare in normal rabbit aortas compared with humans and swine, as has been shown by the present study and previous investigations of surface preparations. Light microscopy was used to study the development of immune complex-induced hematogenic macrophage infiltrations in 26 rabbits from the 4th ...
Malorny U - - 1988
The kinetics of appearance of MIF+ cells was investigated in experimental contact dermatitis using a monoclonal antibody (7D10) against murine MIF which was reacted with cryostat sections of tissues and detected by the indirect immunoperoxidase test. Four groups of BALB/c mice were investigated: (1) sensitized with 2,4-dinitrofluorobenzene (DNFB); (2) unsensitized ...
Tabas I - - 1987
Cholesteryl ester (CE) accumulation in arterial wall macrophages (foam cells), mediated by the intracellular enzyme acyl coenzyme A:cholesterol acyl transferase (ACAT), is a prominent feature of atherosclerotic lesions. However, native low density lipoprotein (LDL) does not cause activation of ACAT or CE accumulation in cultured mouse peritoneal macrophages despite both ...
Weinstock J V - - 1987
Enteric immunization with schistosome ova results in a diminished granulomatous response. This study explored a mechanism by which enteric immunization may decrease granuloma size. Granulomas from livers of acutely infected mice were dissociated and the dispersed cells were depleted of macrophages. As defined by a direct in vitro migration inhibition ...
Quinn M T - - 1987
Previous studies in this laboratory established that low density lipoprotein (LDL) incubated with cultured endothelial cells, smooth muscle cells, or macrophages undergoes free radical-catalyzed oxidative modification that generates lipid peroxides and extensive structural changes in the LDL molecule. The oxidatively modified LDL strongly inhibited chemotactic responses of the mouse resident ...
Lopes-Virella M F - - 1987
To determine whether stimulation of macrophages with products related to, or released as a consequence of, infectious processes could play a role in inducing the formation of foam cells, we studied the metabolism of native and acetylated low density lipoprotein (LDL) by human macrophages stimulated with lipopolysaccharide (LPS), muramyl dipeptide ...
Marcus Z H - - 1987
Human seminal plasma from normal or patients with abnormal parameters of the ejaculates contains an inhibitory material that expresses potent in vitro inhibitory activity on PHA-M-induced blast transformation and NK activity. Using the test of inhibition of NK activity, the semen samples from individuals with higher concentrations of fructose had ...
Okuyama H - - 1986
These experiments were undertaken to clarify whether or not suppressor macrophages contribute to deficiency of delayed-type hypersensitivity induced by BCG CW immunization in B6/lpr mice. Addition of indomethacin in vitro did not increase MIF production by immunized lpr lymph node cells. Adherent cells in lymph node cell suspensions from lpr ...
Yatsu F M - - 1986
Foam cells are lipid-laden macrophages derived primarily from circulating mononuclear cells and are a characteristic feature of atheromatous lesions. The exact role of these foam cells in the pathogenesis of atherosclerotic lesions remains uncertain, but one potential function is to take-up and process excess interstitial arterial lipoproteins, suggested by their ...
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