Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0220723 (PCA)
 4,687 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Electron spin resonance spectrometric studies of Mn2+ free radical in the cauda epieymal sperm suspensions of normal, vasectomized and vasectomized plus ascorbic acid treated rats were conducted. In each case, the characteristic 6 hyperfine line-spectrum of g=2.003 at a magnetic field of 3390 gauss was obtained. Healthy adult male albino rats of the Holtzman strain were used for the experiments. Analysis of the spectra showed that the spin concentrations of free radical of the experimental groups were not significantly different from those of the control. Bilateral vasectomy was performed by the standard technique used in human beings. The rats were divided into 3 groups: normal intact control; bilaterally vasectomized for 10 days; and, bilaterally vasectomized and given ascorbic acid orally (100 mg/day/animal) for 10 days. The sperm suspensions were prepared in a known volume of .9% saline solution. Equal amounts of 10% PCA were added to the sperm suspension. Considering the importance of Mn2+ in various reproductive functions, it is evident that vasectomy does not affect the utilization of Mn2+ by epididymis.
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PMID:Preliminary studies on manganese free radical in vasectomy. 75 Apr 26

Mouse and rat IgE fix firmly to the peritoneal mast cells from the other species, sensitizing them for anaphylactic reaction. Sensitization with IgE can be demonstrated by inducing degranulation either with specific antigens or with corresponding anti-IgE. Sensitization of rat mast cells by mouse IgE antibodies is more easily obtained than that of mouse mast cells by rat IgE antibodies. In this case, anti-IgE-induced degranulation is higher than antigen-induced degranulation. Heterologous sensitization by IgE is time requiring and temperature-dependent. Its kinetics depend upon IgE concentration. Cross-reactions between IgE from one species and anti-IgE from another species have been observed: anti-IgE for one species is able to neutralize PCA reaginic activity of sera from the other species; anti-rat IgE induces degranulation of mouse actively sensitized mast cells. The results suggest strongly that there exists a structural and functional similarity between the IgE molecules from the two species.
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PMID:Mouse and rat IgE Cross-sensitization of mast cells and antigenic relationships. 80 16

Precipitation tests using properly absorbed rabbit antisera revealed that PCA extracts of DMH-induced rat jejunal and colonic adenocarcinomas contain an antigen that is not detectable in extracts of normal rat tissue or other rat tumors. This rat tumor antigen was detected in extracts of normal rat colon by employing the much more sensitive procedure of tanned cell hemagglutination inhibition, however, the concentration of the antigen in tumor was about 250-fold higher than in normal colon. Similar to human CEA, the rat tumor antigen was found to be heat stable, contained glycoprotein, migrated as a beta-globulin, and appeared at a high concentration in fetal intestines, however, the rat tumor antigen was serologically distinct from human CEA.
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PMID:A thermostable antigen characteristic for carcinogen-induced rat intestinal tumors. 81 15

Guinea-pigs produced both gamma1 and gamma2 antibodies against Escherichia coli K12, W3110/SM when they were injected intraperitoneally with a suspension of heat-killed bacteria without adjuvant twice a week for 12 weeks. The antibodies were separated by DEAE-cellulose chromatography. The gamma1 antibodies gave PCA reaction against soluble antigens prepared from sonicated E. coli, but the gamma2 antibodies did not. Both gamma1 and gamma2 antibodies induced complement-mediated bactericidal reaction against the homologous bacteria. In the case of gamma1 antibodies presensitization of bacteria with the antibodies before the addition of complement enhanced their bactericidal activity to a degree, EGTA inhibited the bactericidal activity of gamma2 antibodies, more than that of gamma1 antibodies. It is suggested that the gamma1 antibodies kill bacteria via the alternative pathway of complement activation, whilst the gamma2 antibodies exert their bactericidal activity mainly through the classical pathway.
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PMID:Immune bactericidal reactions by guinea-pig gamma1 and gamma2 antibodies. 81 78

Dental plaque anaerobes may be associated with the etiology of periodontal disease. This has created an interest in the potential pathogenicity of oral anaerobes. We compared the metabolic activity of anaerobic corynebacteria (C. parvum, C. anaerobium) and corresponding aerobic species (C. diphtheriae, C. xerosis). The anaerobes exhibited lower levels of RNA synthesis, ranging from 5 to 10 fold over the aerobes. We further examined these anaerobes, plus Actinomyces naeslundi N16 (isolated from the anaerobic region of periodontally-diseased tissues), for the influence of redox potential on RNA level and antigenic function. Notable increases in RNA were found at specific Eh levels; the extent and direction of the changes varied with the different organisms. This environmental feature appeared to effect corresponding changes in agglutinability and PCA reactivity with antisera against the anaerobes cultured at different redox potentials. For example, while antisera against certain organisms (C. parvum, A. naeslundi) cultured under the most reuced conditions showed an intense PCA reaction, other antisera against the same organism cultured under less reduced conditions were non-reactive. Hence, alterations in redox potential may lead to alteredetabolism and to altered antigencity. Our results imply such a microbial response to environmental stress.
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PMID:Level of redox potential as a possible contributing influence in the pathogenicity of oral anaerobes. 81 53

The skin of congenitally athymic nu/nu mice is rich in mast cells which stain metachromatically, contain histamine and 5-hydroxytryptamine, and participate in the PCA reaction. Mast cells of athymic mice have thus the attributes of normal mast cells.
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PMID:Mast cells in the skin of normal, hairless and athymic mice. 81 24

Biologic properties of antibodies are known to be mediated by the Fc portion of the H chains. In the present study such properties as complement fixation, cutaneous anaphylaxis, and macrophage cytophilia were examined in relation to the CH2 and CH3 domains of rabbit IgG. Fragments containing but one of these domains were prepared from plasmin and papain digests. Facb fragments of anti-DNP antibodies, together with the antigen DNP-BSA, were able to fix complement by the classical pathway, a result which implicates the CH2 domain; however, guinea pig Fab fragments directed to regions of the rabbit antibody molecule other than CH2 were able to inhibit complement fixation. Facb fragments were unable to mediate PCA or reverse PCA reactions in guinea pigs, nor were CH3 fragments active in tests of reverse PCA or inhibition of PCA. These results suggest that the entire Fc region is needed for cutaneous anaphylaxis. The ability to bind to guinea pig lung macrophages was studied with a rosette technique. Facb fragments were active whereas CH3 fragments failed to inhibit. It is suggested that although some effector functions of antibodies can be assigned to individual domains, others require the entire Fc region.
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PMID:Biologic activities of rabbit immunoglobulin G in relation to domains of the Fc region. 81 12

Incubation of histamine with guinea-pig skin or with a particle-free supernatant fraction of homogenized skin caused progressive temperature dependent decay of histamine activity. The loss of histamine activity was due to enzymic degradation of histamine by diamine oxidase since it was reversed by aminoguanidine. Burimamide caused a similar though less marked reversal of histamine degradation. Studies using S-adenosylmethionine, an essential cofactor of histamine-N-methyl transferase suggested the presence in a latent form in guinea-pig skin of a second pathway for enzymic degradation of histamine involving N-methylation. Pretreatment of guinea-pigs with aminoguanidine caused marked potentiation of the 72 hr homologous PCA reaction which suggests that histamine degradation is an important modulating factor in immediate allergic reaction in this species.
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PMID:Enzymic histamine metabolism in guinea-pig skin and its role in immediate hypersensitivity reactions. 82 4

Sera from patients with allergic asthma to castor bean dust were tested for specific antibodies in the red cell linked antigen-antiglobulin reaction (RCLAAR) using antiglobulin sera specific for IgE and the four subclasses of IgG. Approximately one-third of the patients with specific IgG antibodies had an antibody response that was predominantly in the IgG4 subclass. Two patients who were thought not to be sensitive to castor bean allergen, despite long exposure to the dust, did not have detectable IgE antibodies, but had high titres of IgG antibodies that were predominantly IgG4. Specific IgG4 antibodies to castor bean allergen were heat stable, did not appear to passively sensitize monkey skin in the PCA reaction and did not passively sensitize human basophils for the rosette reaction with castor bean-coated red cells.
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PMID:The IgG subclasses of antibodies to castor bean allergen in patients with allergic asthma: detection of a high incidence of antibodies of the IgG4 subclass. 83 59

In adult C57BL/6 mice, a high-responder strain to ovalbumin, PCA and HA antibodies appeared at the same time after immunization. In young mice, on the other hand, the capacity to produce IgE antibodies against ovalbumin developed earlier than that to produce IgM or IgG antibodies.
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PMID:Relationships between IgE antibody production and other immune responses I. Ontogenic development of IgE antibody-producing capacity in mice. 83 14


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