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Biomedical subjects

J Ring

Publications and source records attributed to J Ring.

At least 559 records · Page 31Linked to original sources

Anaphylactoid reactions to infusions of plasma protein and human serum albumin. Role of aggregated proteins and of stabilizers added during production.

Six patients suffering from anaphylactoid reactions after infusion of pasteurized plasma (PP) or human serum albumin (HSA) were investigated. Clinical symptoms ranged from urticaria and hypotension to cardiac arrest. Immunoglobulin levels, especially of IgA, were normal, as were concentrations of complement factors C3, C4 and factor B. In skin and lymphocyte transformation tests patients, with the exception of one severely allergic to protein, did not react to the monomeric pure HSA. Five out of six patients reacted against HSA aggregates and three patients to the HSA modified by caprylate added as stabilizer during commercial HSA production. It is concluded that the anaphylactoid reactions developing after PP or HSA infusion result from a non-specific reaction to protein aggregates and in some cases possibly from a specific immune response to the caprylate-modified HSA.

Anaphylaxis↗

Effects of radiopaque contrast media on the microcirculation of the rabbit omentum.

Histamine concentration in plasma was measured and the microvasculature studied after injections of radiographic contrast materials and hypertonic NaCl solutions. Only 8 ml/kg of contrast material caused a prolonged decrease in systemic and microvascular pressure and a drop in erythrocyte velocity. Concomitantly, a significant increase in plasma histamine concentration was observed after two minutes. Signs of cellular defects and constriction of arterioles were noted after several minutes. These findings suggest that the hyperosmolality of the radiopaque materials tested could initiate the microhemodynamic reactions but is not responsible for cellular and endothelial damage in the microcirculation of the rabbit omentum.

Animals↗

In vitro histamine and serotonin release studies in atopic dermatitis.

6 patients suffering from severe atopic dermatitis with high serum IgE were investigated. 3 of the patients had elevated plasma histamine levels (1.5-2.0 ng/ml). Compared to 9 nonatopic normal volunteers, the patient showed increased in vitro histamine release from peripheral leukocytes after stimulation with iothalamate and methacholine: while there was no significant histamine release at a methacholine concentration of 10(-4) M in normals, 4 of the patients with atopic dermatitis showed measurable histamine release under these conditions in vitro. The uptake of radiolabeled serotonin by platelets in vitro was decreased in 2 of the patients. There was no significant difference in serotonin release induced in vitro by different concentrations of thrombin, epinephrine and methacholine; 2 patients showed an increased platelet release reaction after iodipamide stimulation. It is concluded that a general tendency to release vasoactive mediators, even after 'nonimmunologic' stimulation, might play a role in the pathogenesis of atopic dermatitis.

Adult↗

Alteration of human blood cells and changes in plasma mediators produced by radiographic contrast media.

In vitro incubation of human blood cells with iodinated radiographic contrast media (RCM) produced marked effects which were dose-dependent: erythrocytes showed crenation which was reversible; neutrophil leukocytes released the lysosomal enzyme beta-glucuronidase; basophil leukocytes released histamine; and platelets released serotonin as well as beta-glucuronidase. The release reaction could not be attributed to cell lysis, as demonstrated by the release of the cytoplasmic enzyme lactic dehydrogenase (LDH). In normal human serum, RCM produced activation of the complement system with lysis of cells. This RCM-induced complement activation seemed to occur via the alternate pathway. Stabilizers and cations present in the clinically used RCM solutions did not produce any complement changes.

Basophils↗

Human blood cells ultrastructural changes and mediator release after exposure to roentgenographic contrast media.

Adverse reactions to roentgenographic contrast media (RCM) are associated with the release of mediators including complement components (anaphylatoxins), histamine and serotonin. In an in vitro study of platelets and leukocytes from 20 healthy individuals, RCM-induced release of granules from basophils and platelets was correlated with the release of histamine and serotonin respectively. The release of histamine from basophils was augmented in the presence of exogenous complement; in contrast, the release of serotonin from platelets was not dependent on the addition of exogenous complement. Although individual differences were noted, iothalamate most effectively released serotonin, whereas diatrizoate most effectively released histamine.

Adult↗

Elimination and organ distribution of intravenously administered allogeneic and xenogeneic IgG modifications. (Standard IgG, F (ab)2-fragments and beta-propiolactone treated IgG) in dogs.

Dog IgG was produced by fractionation procedures used for the production of clinically used i.v. gammaglobulins. Chemical modification of dog IgG was done by pepsin or beta-propiolactone treatment. The intravascular half-life of beta-propiolactone IgG was 8.5 +/- 2.1 days compared to 4.5 +/- 1.6 days of pepsin treated IgG. Tissue concentrations of radioactive labelled beta-propiolactone IgG were generally higher than of pepsin digested IgG. Pepsin treated Igg was degraded to a significantly higher extent (26% of the administered radioactivity was bound to fragments smaller than 6000 MW after three days) than beta-propiolactone IgG (9% fragments after the same interval, P less than 0.001). It is concluded that the short intravascular half-life of pepsin IgG cannot be explained by increased extravascular filling, but is due to rapid degradation and excretion via the kidneys. There was no obvious difference in elimination and organ distribution between standard and beta-propiolactone IgG.

Animals↗

Synthesis of mouse mammary tumor virus ribonucleic acid in isolated nuclei from cultured mammary tumor cells.

Glucocorticoid hormone treatment of GR cells, a cultured line derived from mouse mammary tumor tissue, selectively stimulates the rate of transcription of integrated proviral genes specifying mammary tumor virus (MTV). We have incubated isolated nuclei from these cells under conditions in which all three endogenous RNA polymerases appear to be active. RNA synthesized in vitro is distinguished from preexisting nuclear RNA by labeling the in vitro products with [3H]CTP, and the level of MTV RNA synthesis is measured by molecular hybridization with unlabeled viral DNA. Synthesis requires the addition of nucleoside triphosphates, and is inhibited by actinomycin D. Pretreatment of GR cells with dexamethasone, a synthetic glucocorticoid, has no significant effect on the amount of total RNA synthesis in isolated nuclei. In contrast, synthesis of MTR RNA is stimulated 10-20-fold in nuclei from dexamethasone-treated cells relative to untreated control nuclei; the sensitivity of in vitro viral RNA synthesis to inhibition by alpha-amanitin suggests that it is carried out exclusively by RNA polymerase II. The fraction of total RNA synthesis which is viral specific (about 0.2-0.4% in nuclei from dexamethasone-treated cells and 0.01-0.03% in controls) is similar to that detected in pulse labeled RNA from whole GR cells in culture. Our procedures for labeling and hybridization of RNA appear to avoid artifacts recently noted in other in vitro transcription systems.

Amanitins↗

[Antigen-elimination technic. An in vivo method for studies of the human immune response against horse gamma globulin].

In 20 patients treated with antilymphocyte horse gamma-globulin (ALG) the immune response was tested by means of the antigen elimination technique before, during and after ALG-therapy. The comparison of this method with agargel diffusion test, indirect hemagglutination and skin tests showed that immunization of patients against horse protein is indicated earlier and more reliable with the antigen elimination. Therefore this technique should be utilized during a therapy with foreign proteins especially when the results of other immunological test methods are insufficient.

Animals↗

Complement and immunoglobulin deposits in the skin of patients with atopic dermatitis.

The immunofluorescent patterns of uninvolved and involved skin biopsies from eight patients with atopic dermatitis were studied, using direct immunofluorescence techniques to identify deposits of the immunoglobulins G, A and M as well as the complement factors C1q, C3, C4, C5, factor B and properdin. Immunoglobulin deposits (mainly IgG) were found in five patients, complement deposits in three patients in the basement membrane zone. In three patients the immunofluorescence was positive for C3, in two patients for C1q, C4 and C5. Regarding the factors of the alternative pathway of the complement system, two patients showed deposits of properdin, one of factor B. The changes were not confined to the eczematous lesions, but were found in uninvolved skin too. The most prominent changes were observed in patients with severe disease.

Adolescent↗

Quantitation of passive cutaneous anaphylaxis (PCA) by using radiolabelled antigen.

The major problem of detecting reaginic antibody by passive cutaneous anaphylaxis (PCA) is the quantitation of the dye reaction. Radiolabelled antigen was used in an attempt to quantitate the PCA reaction (Radio-PCA). Antisera containing reaginic antibody against human serum albumin (HSA) were produced in rabbits. These antisera were injected into normal rabbit skin in different dilutions. Twenty-four hours later HSA was injected intravenously either with Evans Blue or as 125-I-HSA. Radioactivity found in antibody-containing skin was significantly higher than in control specimens containing saline or normal rabbit serum, as low as antiserum dilutions of 1:1,000. Compared with the Evans Blue technique Radio-PCA was able to distinguish quantitatively between different antiserum dilutions at a higher level of statistical significance.

Animals↗

In vitro histamine and serotonin release by radiographic contrast media (RCM). Complement-dependent and -independent release reaction and changes in ultrastructure of human blood cells.

Peripheral leucocytes and platelets from twenty healthy volunteers were incubated in vitro with radiographic contrast media (diatrizoate-Hypaque, iothalamate-Conray and iodipamide-Cholografin) under varying conditions. All radiographic contrast media (RCM) were able to induce histamine release from peripheral leucocytes and the release reaction was dose-dependent. There were individual differences in the sensitivity of leucocytes to different RCM. The highest values (up to 80% histamine release) were found with high concentrations (0.07-0.3 M) of diatrizoate. The addition of normal human serum (NHS) to the reaction mixture led to a further increase in histamine release (P is less than 0.01), probably due to complement activation. The mechanism seems to be mediated by proteins of the alternative pathway, because serum depleted of complement components (factor B, factor D, properdin) did not show this synergistic effect. IgG-depleted serum, however, was able to show the augmented release reaction. Washed platelets incubated with RCM released serotonin in a dose- and time-dependent reaction. The most powerful serotonin-releasing RCM was found to be iodipamide, which produced a release reaction in all people investigated at concentrations of 0.04-0.09 M, while diatrizoate and iothalamate were effective only in half of the tested individuals at high concentrations (0.3 and 0.2 M respectively). The addition of plasma proteins to the reaction mixture inhibited the serotonin release quantitatively. There was no difference in inhibitory potency between autologous and heterologous plasma or serum; sera depleted of various complement components showed similar effects as NHS. The serotonin release was not due to platelet lysis, as determined by the concentration of lactic dehydrogenase present in the supernatant during serotonin release. Incubation of the leucocytes with RCM produced ultrastructural changes, including degranulation of basophils, aggregation of platelets and infiltration of the aggregates by polymorphonuclear leucocytes. The most prominent changes were observed when complement was present in the reaction mixture.

Basophils↗

[Sideeffects of colloids (author's transl)].

A prospective controlled trial during 1975 and 1976 has revealed that none of the colloids in clinical use (plasma protein solution, gelatine, hydroxyethylstarch and dextran) is free from the risk of anaphylactoid reactions. Even though the incidence of anaphylactoid reactions is low (0.03%), lethal outcome might be encountered. Between the colloids differences exist as far as manifestation (skin, circulatory and respiratory system) and degree of severity (I--IV) of anaphylactoid reactions are concerned. Since the underlying pathomechanisms have not been elucidated yet, true prophylactic measures are unknown. Therefore, it is mandatory to control the patient very carefully at the beginning of infusion; early symptoms of anaphylactoid reactions should trigger immediate therapeutic measures. Recent findings showed that the anaphylactoid reactions to dextran might be elicited by immune complexes. A new model was developed to investigate the chances of specific prophylactic procedures.

Anaphylaxis↗