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)

The antigen-induced release of SRS-A and histamine was studied in the guinea pig and rat using whole and fractionated antiserum preparations. Guinea pig 7Sgamma(1)-antibody sensitized sliced guinea pig lung tissue for antigen-induced release of both SRS-A and histamine; neither substance was released from lung tissue prepared with 7Sgamma(1)-antibody. Rats injected intraperitoneally with hyperimmune rabbit or rat antiserum released only SRS-A in significant amounts when challenged with antigen by the same route. A definite time interval between the injection of antiserum and challenge with antigen was required for optimal release of SRS-A. Fractionation of rat antiserum demonstrated that the immunoglobulin responsible for most of the SRS-A release from rat peritoneal tissue was a gammaG-antibody or fraction thereof. Acting in this capacity, the gammaG-antibody or its subfraction may be considered a second type of homocytotropic antibody. Fractions of rat antisera containing the first type of homocytotropic antibody, i.e. antibody mediating release of histamine and serotonin, prepared peritoneal tissues for the release of large amounts of these pharmacological agents and only small amounts of SRS-A. Two different mechanisms for the production of PCA lesions in the rat were considered. One of these involves the antigen-induced release of histamine and serotonin from mast cells sensitized by homocytotropic antibody. This reaction has an optimal latent period of 24-72 hr. The second mechanism involves the local combination of antigen with "hyperimmune" heterologous or homologous antisera. This reaction can be elicited after a latent period of 4 but not 24 hr; host complement and leukocyte lysosomal enzymes, as well as SRS-A, may be involved.
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PMID:Antibodies involved in antigen-induced release of slow reacting substance of anaphylaxis (SRS-A) in the guinea pig and rat. 416 57

The effects of RU-31156 on type I allergic reactions were studied and the following results were obtained. Seven-day homologous PCA in guinea pigs was significantly inhibited by oral doses of this drug. The maximum inhibition was observed when the drug was given 30 minutes prior to challenge. Forty-eight-hour homologous PCA was significantly inhibited in rats, and this inhibition was maximal when the drug was given 10 minutes prior to challenge. Orally-administered RU-31156 gave significant inhibition of induction of experimental asthma symptoms in guinea pigs when it was given one or two hours prior to challenge. In addition, the drug significantly inhibited the asthmatic reaction of experimental asthma in rats when it was given 10 minutes prior to challenge. RU-31156 significantly inhibited histamine and SRS-A release from the lung tissue of passively sensitized guinea pigs. The combined use of isoproterenol or theophylline with RU-31156 did not enhance the inhibitory activity of the drug. RU-31156 did not produce any effect on the histamine release induced by calcium ionophore A 23187. RU-31156 inhibited the Schultz-Dale reaction in the tracheal muscle and the ileum of guinea pigs, but it did not show any antihistaminic in these organs.
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PMID:Inhibition of immediate hypersensitivity reaction by a new drug, RU-31156. 620 30

The discovery of anaphylaxis by Portier and Richet that reinjection of a substance caused disease instead of immunity was sensational as it was against the prevailing DOGMA. Passive transmission of hypersensitivity with human antibody by Prausnitz (the P-K reaction, 1921) was an important step in the study of human hypersensitivity. Anaphylaxis was shown to be the consequence of liberation of vasoactive substances (histamine and SRS-A) from mast cells when the allergen crosslinks two IgE molecules fixed to mast cell Ig receptors (Ovary, 1961). The use of smooth muscle contraction (Dale, 1913) and vascular permeability increase (PCA, Ovary, 1948) became important for experimental studies. The clonal selection of antibody formation (Burnet, 1929) opened a new era in immunological concepts. The demonstration of the Fc receptor on mast cells (Ovary, 1961) called attention to the importance of cellular receptors. The carrier effect (Ovary & Benacerraf, 1963) was explained by recognition by T cell receptors of a processed carrier fragment complexed to Ia molecules (Unanue, Grey, 1981). Human IgE responsible for allergies was discovered in 1965 by K. & T. Ishizaka. Tonegawa in 1973 destroyed the "one gene-one protein" DOGMA, showing that the immunoglobulin, germline gene is discontinuous: i.e., composed of exons (which will form the Ig molecule) separated by introns. The CD4 cells were subdivided into Th1 and Th2 cells (Mosmann & Coffman, late 1980's). The Th2 secretes IL-4 necessary for IgE production (Paul, Vitetta, & others, early 1980's). B cells multiply before antibody production or become memory B cells, but what causes a B cell to become a memory cell is not known. The B cell does not change specificity but can switch the isotype using "switch recombinase" and the s segment of the Ig molecules (Honjo, early 1980's). IgE production was shown to be suppressed by lymphokines, such as IFN-gamma and IL-2. A great progress in understanding the mechanism of allergic reaction has been the result of intense investigations by many scientists. A more complete understanding, better prophylaxis and an improved treatment are the goals of the near future.
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PMID:Immediate hypersensitivity. A brief, personal history. 769 78

Introduction: About 22% of pregnant women are anemic in Ethiopia, but there is a large variation across the country. Hence, the aim of this study identifies the prevalence of anemia and associated factors among pregnant women attending prenatal appointments in Dembia District, northwest Ethiopia.Methods and materials: A facility-based, cross-sectional study was conducted among 713 pregnant women. A multi-stage, stratified sampling technique was used to select the study participants. A structured and pretested questionnaire, laboratory data, and chart review were used to collect data. Bivariate and multivariate logistic regression analyses were used to identify factors associated with anemia in pregnant women.Results: Prevalence of anemia was 32.4% with a majority of these having moderate anemia. Type of health center being rural/urban health center, water sources, days since fasting, 4 weeks of iron supplementation, craving unusual foods, mid-upper arm circumference scores, and decision power were significant predictors of anemia.Conclusion: The present study suggests anemia among pregnant women attending prenatal in Dembia district was high. Working to enhance adherence to iron supplementation and partner involvement for joint decision-making is recommended to avert prenatal anemia. Health-care providers and programmers are advised to pay special attention to rural and fasting pregnant mothers.Abbreviations: AOR: Adjusted Odd Ratio; CMHS: College of medicine and health sciences; CI: Confidence Interval; HFIAS: Household Food Insecurity Access Scale; RCSI: Reduced Coping Strategies Index; Hgb: Hemoglobin; MCMC: Marco Chain Monte Carlo; EPV: Events per variable; BMI: Body Mass Index; PPS: Population proportionate to size sampling; SRS: simple random sampling; DALYS: Disability-adjusted life years; MUAC: Mid-upper-arm-circumference; WHO: World Health Organization; EDHS: Ethiopian Demographic and Health Survey; SPSS: Statistical package for social science; ANC: Ante natal care; PCA: Principal component analysis; MASL: Meter above sea level; g/dl: gram per decilitre HALE: Health Action Leicester Ethiopia; WDDS: Women's Dietary Diversity Scale.
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PMID:Anemia and Associated Factors among Pregnant Women Attending Prenatal Care in Rural Dembia District, North West Ethiopia: A cross-Sectional Study. 3165 36


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