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

The synthesis and alpha-adrenoreceptor blocking activity of several substituted analogs of the prototype alpha-blocker N,N'-bis-(5-aminopentyl)cystamine (APC) are described. The three optical forms of the analog carrying methyl groups on the carbons alpha- to the sulfurs were synthesized and shown to be equipotent and somewhat less active than APC. The omega, omega'-bis-guanidino analog of APC was less active. Significant improvement in potency was observed only with APC analogs carrying benzyl and substituted benzyl groups on the terminal nitrogens. Linking the terminal nitrogens of APC with a p.xyledenyl group so as to give the 26-membered analog caused a sharp drop in activity. The significance of these results as regards the alpha-receptor topography is discussed.
 ...
PMID:Molecular properties of the adrenergic alpha-receptor. I--Structural requirements for specific covalent occupancy by N,N'-bis--(5-aminopentyl)cystamine derivatives. 3 32

In connection with the elucidation of the possibility of photochemical participation of phycobiliproteins in the primary processes of photosynthesis, the ability of a mixture of phycocyanin + allophycocyanin (PC + APC) for photosensitization of redox reactions in the adsorbed state was investigated. It was shown that adsorbates of PC + APC on Sephadexes G-200 and G-25, diethylaminoethylcellulose, carboxyethylcellulose, Bacto-agar, Lifogel, polyethylene glycol, Dowex 50Wx2, and aluminum oxide are capable of sensitizing the photoreduction of methyl red by ascorbid acid. In this case the effectiveness of the sensitizing action depends on the concentration of the adsorbate, the pigment concentration on the carrier, the pH of the medium, and the nature of the solvent. It was shown that in the case of binding to a carrier, the sensitizing ability of PC + APC increases in comparison with that for pigments in the dissolved state. It is suggested that this is promoted by an increase in the concentration and a mutual approach of the reagents after adsorption, and the possible formation of complexes of some or all the participants of the reaction on the surface of the adsorbent.
 ...
PMID:The photosensitizing action of phycobiliproteins in the adsorbed state. 3 27

We collected Escherichia coli strains from 59 Nepalese porters in 1971 and surveyed for their drug resistance. Drug-resistant E. coli strains were isolated from four porters. (TC. CM. SM. SA. APC.)-resistant strains were isolated from two porters and SA- or APC-resistant strains were isolated from each of the others. The R factors were demonstrated from the multiple-resistant E. coli strains.
 ...
PMID:Drug resistance of Escherichia coli isolated in Nepal. 36 28

The fetus is known to be bacteria-free and is contaminated with bacteria during birth. We examined drug-resistant bacteria in feces of new-born infants to know the distribution of drug-resistant bacteria in a hospital. Among 76 infants examined, we could isolate drug-resistant strains of bacteria from 65 infants (86%). We collected 110 drug-resistant strains of Escherichia coli, Klebisella pneumoniae, and Pseudomonas aeruginosa, and could isolate 53 strains (48%) carrying R plasmids; they being 33R (TC.CM.SM.SA.APC) and 20R (TC.CM.SM.SA) plasmids. The data indicated that R plasmids with the same resistance patterns were distributed in a hospital, and new-born infants were contaminated with bacteria carrying R plasmids, although the contamination rate of drug-resistant bacteria in the intestinal flora was very low.
 ...
PMID:Isolation of drug-resistant bacteria from newborn infants. 40 39

1. The initial site of damage in analgesic abuse is the renal medulla and the characteristic lesion is renal papillary necrosis. The papillary necrosis appears to be an ischaemic infarct. The cortical lesion of chronic interstial nephritis is a non-specific change and secondary to obstruction to tubules in the necrotic medulla. 2. Medullary perfusion and the concentration mechanism appear to be important factors in the genesis of renal papillary necrosis. 3. Experimental and clinical studies suggest that abuse of compound analgesics containing aspirin, phenacetin and caffeine result in renal papillary necrosis and the clinical syndrome of analgesic nephropathy. In the APC mixture aspirin appears to be the major nephrotoxic agent while phenacetin plays a synergistic but secondary role in the renal nephrotoxicity.
 ...
PMID:Pathology, aetiology and pathogenesis of analgesic nephropathy. 107 Sep 95

Analgesic nephropathy is part of a wider clinical syndrome associated with the abuse of APC compounds, that is, a minimum total intake of 2 kg of aspirin or phenacetin. Ischaemic heart disease and premature aging are newly recognized aspects of the analgesic syndrome. The diagnosis of analgesic nephropathy can be made precisely by the radiological demonstration of renal papillary necrosis. The most important aspect of management of established analgesic nephropathy and renal insufficency is total avoidance of all non-steroid antiinflammatory agents and this is commonly associated with stabilization or improvement in renal function. In the APC mixture, aspirin appears to be the major nephrotoxic agent while phenacetin and paracetamol play a secondary and synergistic role in the nephrotoxicity.
 ...
PMID:Analgesic nephropathy. 108 2

Ag-presenting cells provide at least two distinct signals for T cell activation. T cell receptor-dependent stimulation is provided by presentation of a specific peptide Ag in association with MHC molecules. In addition, APC also supply costimulatory signals required for T cell activation that are neither Ag- nor MHC restricted. One such costimulatory signal is mediated via the interaction of B7 on APC with the CD28 receptor on T cells. Recently, CTLA-4 has been shown to be a second B7 receptor on T cells. In the present report, we have examined the expression of CD28 and CTLA-4 on a panel of resting and activated normal T cell subsets and T cell clones by RNA blot analysis in an attempt to determine whether their expression defines reciprocal or overlapping subsets. CD28 was detected in resting T cells, whereas CTLA-4 was not. After stimulation with PHA and PMA for 24 h, CTLA-4 mRNA was expressed in both the CD4+ and CD8+ subsets as well as in CD28+ T cells. We examined 37 human and six murine T cell clones that had been previously characterized for their cytokine production. After activation, CTLA-4 and CD28 mRNA were coexpressed in 36 of 37 human T cell clones and all six murine T cell clones. These included T cells of CD4+8-, CD4-8+, and CD4-8- phenotypes as well as clones with Th1 and Th2 cytokine profiles. In contrast, CD28 but not CTLA-4 mRNA was detected in leukemic T cell lines and myelomas. CTLA-4 and B7 mRNA but not CD28 mRNA was detected in two long term HTLV-I-transformed T cell lines. These data demonstrate that CD28 and CTLA-4 mRNA are coexpressed in most activated T cells and T cell clones, providing evidence that they do not define reciprocal subsets. Moreover, they are consistent with the hypothesis that B7 transmits its signal through a single receptor, CD28, on resting T cells, and multiple receptors, CD28 and CTLA-4, on activated T cells.
 ...
PMID:CTLA-4 and CD28 mRNA are coexpressed in most T cells after activation. Expression of CTLA-4 and CD28 mRNA does not correlate with the pattern of lymphokine production. 128 Nov 86

T lymphocytes recruited into the skin can experience several different outcomes. On the one hand, they may be recruited by adhesion molecules and chemoattractants to enter the perivascular space, but never undergo activation. Other T cells undergo activation and further differentiation under the influence of the cutaneous milieu. These activated lymphocytes then coordinate specific and non-specific immune responses characteristic of inflamed tissue. We have explored two models for studying the activation and function of skin infiltrating T lymphocytes (SIL's). In the first model, we have identified a family of Langerhans cell-related professional dendritic antigen presenting cells that exist in the epidermis and dermis of normal skin, atopic skin, and mycosis fungoides skin. These have APC abilities to activate freshly recruited resting blood T cells that are distinct from another family of macrophage-related cells abnormally present in sunburned or psoriatic skin. In the second model, we examined the function of cells that have already been recruited into the skin of patients with psoriasis and mycosis fungoides. Lesional psoriasis and mycosis fungoides T cells exhibited a variety of T cell receptor gene rearrangements, conclusively demonstrating that heterogeneous populations of T lymphocytes exist in inflamed human skin. From psoriasis, clones were identified that were particularly effective at inducing normal keratinocytes to assume "psoriatic" phenotypic features and functions. Thus, lesional psoriatic SIL's could induce HLA-DR, ICAM, and CDw60 on normal keratinocytes. In addition, psoriatic SIL's induced increased keratinocyte proliferation and cytokine profile changes characteristic of psoriatic epidermis.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Skin-infiltrating lymphocytes in normal and disordered skin: activation signals and functional roles in psoriasis and mycosis fungoides-type cutaneous T cell lymphoma. 129 60

The APC gene is responsible for familial adenomatous polyposis and is considered to be a tumor suppressor gene associated with development of sporadic colorectal tumors. Here we report the disruption of the APC gene caused by somatic insertion of a long interspersed repetitive element (LINE-1 sequence) into the last exon of the APC gene in a colon cancer. The inserted sequence was composed of a 3' portion of the LINE-1 consensus sequence and nearly 180 base pairs of polyadenylate tract. Furthermore, since an 8-base pair target site duplication was observed, retrotranscriptional insertion of an active LINE-1 sequence is suspected as the cause of this insertion event. This is the first report of the disruption of a tumor suppressor gene caused by somatic insertion of a mobile genetic element.
 ...
PMID:Disruption of the APC gene by a retrotransposal insertion of L1 sequence in a colon cancer. 131 68

Recognition of viral Ag and of the envelope glycoprotein of HIV (gp120) in particular by human Th cells is critical in the immune response to the viral Ag which includes antibody production and generation of cytotoxic cells. Procedures to increase antigenicity of gp120 are highly desirable in a vaccine perspective. Therefore, to induce activation of gp120-specific T cells by a liminal dose of Ag we enhanced uptake of gp120 by exploiting the galactose receptors on APC. Terminal sialic acid residues were removed by neuraminidase treatment from the carbohydrate side chains of the heavily glycosylated gp120. Galactose residues were exposed and hence recognized by galactose receptors on APC. The experiments demonstrated that 1) human monocytes and dendritic cells, but not cells of the B lineage, bear galactose receptor; 2) galactose receptors are indeed involved because enhanced presentation is inhibited by galactose and acetylgalactosamine and competed for by other asialoglycoproteins; 3) galactose receptors mediate internalization of Ag in intracellular compartments that intersect the processing and presenting pathways, resulting in activation of specific T cells; 4) antigenicity of gp120 for specific T cells can be enhanced by the exposure of galactose residues.
 ...
PMID:Galactose receptors and presentation of HIV envelope glycoprotein to specific human T cells. 131 6


1 2 3 4 5 6 7 8 9 10 Next >>