Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0033036 (APC)
 10,214 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A case of deep-vein thrombosis in a 23-year old woman 1 month after starting oral contraceptives is described, the 1st known incident of defective Protein S activity with normal levels of Protein S but defective APC cofactor. The woman had no known personal risk factors or family history of thromboembolism. She noticed pain and swelling of her right leg, and on admission to the Institute of Internal Medicine of the University of Milan, bilateral leg venography demonstrated occlusion of the right popliteal, femoral and iliac veins. She was treated with intravenous heparin for 10 days, and then warfarin. Protein S is a vitamin K-dependent plasma protein which binds to platelets and endothelial cells and functions as a cofactor for Protein C in the proteolytic cleavage of the activated forms of coagulation factors V and VIII. Persons with Protein S deficiency are at a high risk for thromboembolism. All coagulation laboratory screens were normal on repeated testing of the proband's plasma before initiating therapy, as well as her family members. In this patient total protein S antigen was low normal by EIA and ELISA. APC-cofactor was the only assay clearly abnormal, in the proband, her mother, siblings and maternal uncle; APC- cofactor activity was restored to normal by adding back pure Protein S.
Thromb Haemost 1989 Sep 29
PMID:Familial dysfunction of protein S. 253 Jun 48

In the previous report, we investigated the effects of tissue culture on the APC function of murine epidermal Langerhans cells (LC) in the induction of allo-CTL in vitro, and found that (1) cultured ear LC expressed increased amounts of Ia antigens on their cell surface, and (2) they induced extremely enhanced levels of CTL over those produced by freshly prepared ear LC and also (3) cultured tail LC were proved to be able to induce CTL for the first time. It seemed that tissue culture decreased the functional heterogeneity among the murine ear LC and tail LC in addition to that among Ia+ APC in spleen and in epidermis. In this study, we investigated the culture conditions that increase the APC function of LC. Our data indicate that LC cultured with dermal components exhibited more enhanced APC function than LC cultured in single cell suspension with only epidermal cells. Recent studies indicate that IL-1 and GM-CSF, which keratinocytes release, are essential for freshly prepared LC to mature into highly efficient APC that resemble splenic dendritic cells. We found dermal factors are more important than epidermal ones for LC to mature in tissue culture.
Nihon Hifuka Gakkai Zasshi 1989 Sep
PMID:[The functional maturation of Langerhans cells in CTL induction during tissue culture]. 260 68

Immunologically important among the known biologic activities of IL-1 is its ability to function as a co-factor for responses mediated by lymphokine secreting CD4+ Th cells. In contrast to its known effects in CD4+ T cell responses, IL-1 is not known to play a role in CD8+ T cell responses. In the present study, we have assessed the ability of murine recombinant IL-1 to function as a co-factor for stimulating CD8+ T cells to secrete lymphokines such as IL-2. We found that, in conjunction with either Ag or mitogen, IL-1 is able to stimulate lymphokine-secreting CD8+ T cells. Furthermore, we found that, as a consequence of its stimulation of lymphokine-secreting CD8+ T cells, IL-1 is able to reconstitute MHC class I allospecific cytolytic T lymphocyte responses by cell populations depleted of both accessory cells and CD4+ T cells. These results demonstrate that the biologic activity of IL-1 is not restricted to CD4+ cell responses, and suggests that IL-1 can function as a co-factor for the stimulation of lymphokine-secreting Th cells regardless of their CD4/CD8 phenotype. If IL1 acts directly on lymphokine-secreting T cells or on the APC with which they interact is not yet certain.
J Immunol 1988 Sep 01
PMID:IL-1 as a co-factor for lymphokine-secreting CD8+ murine T cells. 297 May 6

In order better to interpret their physiological role in rat spinal cord, we characterized binding sites of [3H]WB-4101 and [3H]p-aminoclonidine ( [3H] PAC), and determined their regional distribution. These binding sites have characteristics required for, respectively, alpha 1 and alpha 2 receptors of norepinephrine. Binding to these sites is saturable, with Kd values of 0.38 nM and 35 nM for high and low affinity binding sites respectively of [3H]WB-4101; and 1.7 nM, for a single binding site of [3H]PAC. For whole cord, Bmax values are 52 and 320 (high and low affinity sites respectively); and 21 fmol/mg protein. Catecholamines compete stereoselectively for these sites, while selected noradrenergic agents compete with an order of potency corresponding to their relative activity at the alpha 1 and alpha 2 receptors. We conclude that spinal alpha 1 and alpha 2 binding sites have the same pharmacologic properties as corresponding peripheral sites. The alpha 2 and, to a lesser degree, the alpha 1 binding sites vary in concentration with region. Our results support the contention that alpha 2 binding sites subserve neuronal function in the spinal cord.
Eur J Pharmacol 1985 Sep 24
PMID:Pharmacological characterization and regional distribution of alpha-noradrenergic binding sites of rat spinal cord. 299 26

Lymph node cells from 4-wk-old MRL/Mp-lpr/lpr mice, but not from MRL/Mp-+/+ mice, when cultured in vitro for 5 to 7 days, will spontaneously proliferate and produce IL-2. We examined the expression of several cell surface Ag on lymph node cells from MRL/Mp-lpr/lpr mice before and after in vitro culture. There is an increase in the expression of Thy-1, L3T4, IL-2R, T cell activating protein, T cell receptor, and T3 complex on the surface of cultured cells. Cultured cells produced IL-3, IFN-gamma, and small but detectable amounts of IL-1 in addition to IL-2. Gamma irradiation of APC from young MRL/Mp-lpr/lpr mice or treatment of APC with a mAb (J11D) and C, completely abrogated their stimulatory capacity. These experiments suggest that B cells are the predominant APC responsible in the activation of autoreactive T cells in MRL/Mp-lpr/lpr mice. Lymph node cells from C57BL/6-lpr/lpr or C3H-lpr/lpr mice were unable to spontaneously proliferate or produce IL-2. Lymph node cells from (MRL/Mp-lpr/lpr x C57BL/6-lpr/lpr) F1 mice or (C3H-lpr/lpr x MRL/Mp-lpr/lpr) F1 mice did proliferate and produced IL-2 after in vitro culture. Using T cells from these F1 animals and APC from each parental haplotype, we found that APC from MRL/Mp-lpr/lpr mice induced more proliferation and greater amounts of IL-2, when compared to APC from F1 animals. APC from C57BL6-lpr/lpr mice or C3H-lpr/lpr were unable to induce spontaneous proliferation and IL-2 production. Therefore, B cells from MRL/Mp-lpr/lpr mice appear to possess unique features that enable them to activate autoreactive T cells more effectively than B cells from other mice bearing the lpr/lpr gene.
J Immunol 1988 Sep 15
PMID:Autoreactive T cells in MRL/Mpr-lpr/lpr mice. Characterization of the lymphokines produced and analysis of antigen-presenting cells required. 313 46

The corecognition of antigen and class II major histocompatibility complex (MHC) molecules (Ia molecules) by the T-cell receptor is a cell surface event. Before antigen is recognized, it must be taken up, processed, and displayed on the surface of an Ia-bearing accessory cell (antigen-presenting cell, APC). The exact nature of antigen processing and the subsequent associations of antigen with the APC plasma membrane, Ia molecules, and/or the T-cell receptor are not well defined. To further analyze these events, we have characterized the processing and presentation of the soluble polypeptide antigen bovine insulin. We found that this antigen requires APC-dependent processing, as evidenced by the inability of metabolically inactivated APCs to present native antigen to antigen plus Ia-specific T-T hybridomas. The ability of the same APCs to present antigen after uptake and processing showed that this antigen subsequently becomes stably associated with the APC plasma membrane. To characterize the basis for this association, we analyzed its sensitivity to enzymatic digestion. APCs exposed to antigen, treated with phospholipase A2, and then immediately fixed lost the ability to stimulate bovine insulin plus I-Ad-specific hybridomas. In contrast, the ability of these same APCs to stimulate I-Ad allospecific hybridomas was unaffected. This effect of phospholipase is not mimicked by the broadly active protease Pronase, nor is there evidence for contaminating proteases in the phospholipase preparation. These results suggest that one consequence of antigen processing may be an antigen-lipid association that contributes to the anchoring of antigen to the APC membrane. The implications of this model are discussed.
Proc Natl Acad Sci U S A 1986 Sep
PMID:Phospholipase treatment of accessory cells that have been exposed to antigen selectively inhibits antigen-specific Ia-restricted, but not allospecific, stimulation of T lymphocytes. 352 95

High-performance liquid chromatographic (HPLC) methods are described for the structural analysis of clavicepamines, their analogues and branched-chain polypeptides, the analysis in synthetic stages of isopeptides (analysis of half-protected derivatives and purity control of active esters) and the differentiation between alpha- and iso-peptides (such as alpha- and gamma-glutamyl peptides). Pre-column derivatization was used to label the free amino groups for the structural investigation. Dansylated and hydrolysed isopeptides were analysed by HPLC methods based on isocratic separation of alpha-, epsilon- and bis-Dns-lysines using Hypersil, ODS-Hypersil and Partisil PAC columns. For the analysis of peptide active esters, an RP-HPLC method was developed, with methanol-acetonitrile-water mobile phases containing an acidic buffer. Peptides containing alpha-glutamyl residues were analysed for gamma-isomer content in the same system.
J Chromatogr 1986 Sep 24
PMID:High-performance liquid chromatography of isopeptides. 378 21

A method for the culture of retinal Muller cells from adult rats is described. Whereas isolated Muller elements did not grow in a medium composed of MEM + 10% FBS, the addition of supernatant from mitogen activated spleen cells induced a strong proliferative response. The factor(s) responsible for that growth were not species specific, as mouse spleen cells conditioned medium was also an effective stimulant. The highly significant degree of DNA synthesis induced by the supernatant from an S-antigen specific T-helper cell line (reacting to the retinal antigen presented on APC) indicates that the growth promoting activity is not restricted to mitogen driven spleen cells. It is suggested that products of inflammatory cells secreted in the course of intraocular immune processes may contribute to the formation of epiretinal membranes. These products also induced the expression of Ia surface antigens by Muller cells, supporting the hypothesis of a possible involvement in local immune reactions.
Curr Eye Res 1985 Sep
PMID:Long-term culture of Muller cells from adult rats in the presence of activated lymphocytes/monocytes products. 390 67

Murine monoclonal antibodies (MoAb) to three distinct Ia-like molecules were studied for their inhibitory effects on antigen- and alloantigen-induced T cell proliferations. The MoAb were classified into three groups according to the molecules they recognized. Both the group I MoAb reacting with DR molecules and the group III MoAb were capable of inhibiting T cell proliferative responses to PPD- and HSV-Ag-pulsed APC, autologous B-LCL, and alloantigens. On th other hand, the group II MoAb, which reacted with a determinant on the molecule carrying MB1 determinants, was only capable of inhibiting T cell responses to alloantigens. These results suggest that the structure of the molecules correlates with the functional repertoire of the human Ia-like antigens.
J Immunol 1982 Sep
PMID:The role of three distinct Ia-like antigen molecules in human T cell proliferative responses: effect of monoclonal anti-Ia-like antibodies. 617 89

Dose-response curves of blood pressure and of the biochemical components of the renin-angiotensin-aldosterone system were determined during long-term treatment with captopril in 21 hypertensive patients. Captopril was given in biweekly, doubling doses starting with 25 mg 3 times a day until control of blood pressure was achieved or a total daily dosage of 600 mg was reached. Recumbent and standing systolic and diastolic blood pressure fell on 75 mg captopril daily. Increasing the captopril dose did not induce further significant hypotensive effects. The pretreatment level of plasma renin activity (PRA) was a poor predictor of the hypotensive effect of captopril. The rises in PRA and plasma angiotensin I level (PA I) and the decrease in plasma angiotensin II level (PA II) and plasma aldosterone level (PAC) provide biochemical evidence for angiotensin-converting enzyme (ACE) inhibition in vivo. These effects were present on daily doses of 75 to 150 mg captopril.
Clin Pharmacol Ther 1980 Sep
PMID:Dose response in captopril therapy of hypertension. 625 Jul 59


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