Biomedical subjects
A M Saavedra-Delgado
Publications and source records attributed to A M Saavedra-Delgado.
Mast cell numbers in rheumatoid synovial tissues. Correlations with quantitative measures of lymphocytic infiltration and modulation by antiinflammatory therapy.
Synovial biopsy specimens from 20 patients with rheumatoid arthritis were subjected to quantitative analysis for several parameters of inflammation and for enumeration of synovial tissue mast cells. Strong positive correlations were found between numbers of mast cells per cubic millimeter of synovial tissue and the following synovial tissue parameters: inflammatory index (a quantification of lymphocytic infiltration), Leu-3a grade (T helper/inducer lymphocytes), Leu-1 grade (T lymphocyte), and plasma cell grade. A strong negative correlation was found between the synovial mast cell count and the extent of sublining layer fibrin deposition. Correlations between synovial mast cell count and Leu-2a grade, ratio of Leu-3a grade:Leu-2a grade, OKM1 grade, HLA-DR grade, and lining layer thickness grade did not reach statistical significance. In addition, we obtained synovial specimens from 6 of the patients both before and after long-term therapy with oral methotrexate and from 3 of the patients before, and 1 week after, an intraarticular injection of steroid. The 3 patients who had an intraarticular steroid injection showed a 67-96% decrease in the number of synovial tissue mast cells; there was no significant change in the number of synovial mast cells in the tissues of the 6 patients who received oral methotrexate. These observations are the first documentation of a quantitative relationship between the number of mast cells and the number and phenotypic profile of infiltrating lymphocytes in an inflamed tissue, which in this case, is human synovium. Our findings suggest that mast cells are involved in the pathologic interactions in rheumatoid arthritis and might play a role in the early phases of exacerbations of disease activity.
Interactions between food antigens and the immune system in the pathogenesis of gastrointestinal diseases.
This review details the evidence that interactions between food antigens and the immune system may play a role in the pathogenesis of several gastrointestinal diseases. In immediate hypersensitivity reactions to foods involving the gastrointestinal system, in milk-induced gastrointestinal disease in infants and children, and in some forms of hypereosinophilic gastroenteritis, the evidence for the participation of food antigens is extensive. Gluten-induced enteropathy and some forms of dermatitis herpetiformis are also induced by defined food proteins where the response is specific and characteristic. The role of food antigens in the pathogenesis of inflammatory bowel disease is unclear, and warrants further studies.
Typical and atypical mast cells of the rat gastrointestinal system: distribution and correlation with tissue histamine.
Mast cells and histamine are present throughout the rat gastrointestinal system. Typical mast cells, differentiated from atypical mast cells by morphology, staining characteristics, and response to Compound 48/80, were the only mast cell type identified by histology in the cheek, tongue, esophagus, and nonglandular stomach. Atypical mast cells were found in large numbers in the glandular stomach, small and large intestine, and cecum, where they outnumbered typical mast cells by up to 20:1. Gastrointestinal histamine levels varied from 2.6 to 19.3 ng/mg in all tissues surveyed except for the glandular stomach, which contained 26 ng/mg. The amount of histamine per typical mast cell was estimated to be approximately 1.29 picograms; atypical mast cells contained less than 0.15 picograms per cell. Parenteral administration of Compound 48/80 resulted in the degranulation of typical mast cells, but not atypical mast cells, as determined by a fall both in typical mast cell number and a decrease in tissue histamine in areas rich in typical mast cells. These results indicate that striking regional differences in mast cell distribution and tissue histamine levels exist in the rat gastrointestinal system.
The gastrointestinal mast cell in food allergy.
Both clinical observations and experimental data support a primary role for mast cells in the genesis of immediate reactions to foods. Of particular interest is the gastrointestinal mast cell. At its location in the bowel wall it is the first mast cell to degranulate to specific antigen, provided it has antigen specific IgE on its surface. This initial reaction may potentiate entry of further specific antigen into the general circulation, where it can travel to distant sites and degranulate additional mast cells. It is also apparent that gastrointestinal mast cells in animal models have unique properties, including a reported insensitivity to certain degranulating agents and drugs. Such features must be further examined in future attempts to select therapy aimed at preventive treatments for food allergic patients.
Dose-response studies of the suppression of whole blood histamine and basophil counts by prednisone.
If some clinical problems (e.g., radiographic contrast media reactions) arise from mediator release by circulating basophils, prednisone's capacity to prevent such is likely to be at least partly related to its suppressive effects on whole blood histamine and basophil levels. To establish an optimal dosage schedule, 15 healthy male volunteers entered a two-phased study to determine (1) the single dose of prednisone required to produce maximal suppression of histamine and basophil levels and (2) the effects of repeated prednisone doses. Parameters monitored were whole blood histamine, quantitative basophil counts, white blood cell (WBC) and differential counts, and plasma prednisone, prednisolone, and cortisol levels. Fifty milligrams prednisone suppressed whole blood histamine levels as much as a larger dose and also showed a marked effect on circulating basophils and other leukocytes. Three 50-mg prednisone doses given at 6-hr intervals had a greater effect on whole blood histamine and circulating leukocytes than fewer doses. Thus, the commonly used empirical prednisone dosage regimen is supported. One implication of the results of this study is that greater suppression of blood basophils and histamine levels might be obtained by administering the last prednisone dose about 6 hr before procedures in which a very rapid release of mediators from basophils is anticipated.
Through the centuries with food and drink, for better or worse. III.
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Through the centuries with food and drink, for better or worse. II.
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Through the centuries with food and drink, for better or worse.
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Through the Centuries with Food and Drink, for Better or Worse. VIII. The School of Salerno.
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Through the centuries with food and drink, for better or worse. VII.
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Through the centuries with food and drink, for better or worse. VI.
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Through the centuries with food and drink, for better or worse. V.
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Through the centuries with food and drink, for better or worse. IV.
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François Magendie on anaphylaxis (1839).
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Huang-Ti, the Yellow Emperor and the Nei Ching: antiquity's earliest reference to asthma.
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