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Biomedical subjects

A I Tabar

Publications and source records attributed to A I Tabar.

67 records · Page 4Linked to original sources
PubMedDate not supplied

IgE receptors (FcR epsilon) modifications. I. Effect of regulator soluble factors of human IgE synthesis isolated by affinity chromatography.

After isolating the soluble factors and observing their biological activity of "in vitro" IgE synthesis, we decided to study the changes these molecules exercise on the expression of lymphocytes of IgE (FcR epsilon). We saw that the fractions from healthy subjects inhibited the expression of receptors quantified by immunofluorescence, reducing it to 15.5 and 15.75 (p less than 0.01). Three of the fractions from atopic individuals also inhibited this expression, with some average values of 13.75, 11.25 and 15.25, against 23 as the basal levels. Material from pollinic patients acted similarly, obtaining expression percentages of 13 and 14.5 (p less than 0.01). These findings, along with those obtained in the experiment of IgE synthesis, confirmed the presence of regulator factors in IgE synthesis in the 3 population groups, quantitatively different. These factors will be isotype specific and just as what happened in IgG synthesis, there was no modification in the expression of the mentioned immunoglobulin.

Antigens, Differentiation↗
PubMedDate not supplied

Adverse reactions produced by iodinated contrast media.

Given the wide utilization of iodide contrast media for the visualization of the different apparatus of the human being and in the view of the presence of adverse reactions in 50% of the explored patients, we thought it interesting to write this review. In it we intend to show, in a clear and concise way, the different mechanisms implicated in the type of reactions. We also comment on the various actual and future methods that could be useful at the time of detecting and preventing such reactions.

Adrenal Cortex Hormones↗
PubMedDate not supplied

Regulator soluble factors of human IgE synthesis. III. "In vitro" modifications.

With our experience on the production and identification of low molecular weight glycoproteins in supernatants of MLC in atopic, pollen-allergic and healthy individuals and after demonstrating the changes in IgE synthesis in isolated lymphocytes of healthy individuals, we decided to amplify the study to include the effects of the allergic population group. Bidirectional mixed lymphocyte cultures were grown. Afterwards supernatants obtained from chromatography of the same affinity were processed, as described in a previous work. The second fractions derived from the MLC of atopic and pollen-allergic individuals affected IgE synthesis at both concentrations. No modifications in IgG synthesis were observed to be due to the addition of these fractions.

Chromatography, Affinity↗
PubMedDate not supplied

Regulator soluble factors of human IgE synthesis. I. Production and isolation.

The system of IgE response undoubtedly has a special interest, given the role of this immunoglobulin on the pathogenesis of allergic diseases. In the last few years the existence of a regulator mechanism that maintains the synthesis of IgE in low but effective levels has been confirmed. This mechanism consists in the equilibrium between the actions of suppressors and enhancers. These two soluble factors present in the serum and capable of suppressing and enhancing IgE response in control rats have been identified; both have a highly selective activity on IgE, exerting their effect in an antigen-independent form and require specie-specificity. Motivated by these findings, we have applied this experimental system used in rats to humans. Healthy controls were selected as low responders of IgE, atopics as high responders, and asthmatic pollinosis considered as the prototype of allergic disease mediated by IgE. After obtaining the factors mentioned by means of a bi-directional mixed culture in a pool of lymphocytes, we proceeded to their isolation by affinity chromatography in Con-A Sepharose columns. The glycoproteins obtained were afterwards submitted to different techniques of characterization: immunoelectrophoresis in polycrilamide gel, chromatography technique, etc.

Chromatography, Affinity↗
PubMedDate not supplied

Regulator soluble factors of human IgE synthesis: II. Biological activity.

In view of the experiments carried out on rats by various investigators in order to identify and characterize soluble factors that regulate IgE synthesis, we decided to apply these systems to humans through different "in vitro" techniques, and in different population groups. After its production through bidirectional mixed cultures as well as its isolation by column of Sepharose Con-A (affinity chromatography), we proceeded to confirm its biological activity. The modifications produced by these factors on the synthesis of IgE "in vitro" (modification of Phadebast IgE PRIST radioimmunoanalysis technique for low levels) on lymphocytes of controls, atopics and pollinosis with and without immunotherapy were confirmed, as well as the non-modification on IgG synthesis. A considerable increase (greater than 300%) in IgE production in lymphocytes of healthy subjects was observed in relation with the stimulating factor obtained in CML of atopic lymphocytes.

Gene Expression Regulation↗
PubMedDate not supplied

Indomethacin induced vasculitis.

We present a case of a 22 year old male with a personal history of ankylopoyetic spondylitis who has presented in the last year cutaneous lesions characterized by papulo erythematous (palpable purpura) localized in both distal inferior extremities in 3 occasions. These 3 episodes have always coincided with the administration of indomethacin due to increasing articular discomfort. The anatomical pathology of the lesions demonstrated the typical finding of leukocytoclastic vasculitis. The pathogenesis of the cutaneous process is discussed, considering the intervening immunocomplex wherein indomethacin or its metabolites have formed part in its origin.

Adult↗
PubMedDate not supplied

Predictive value of airway resistance in patients affected with pollen rhinitis.

We selected 38 symptomatic pollen-sensitive rhinitic patients without bronchial pathology and with normal pulmonary functional study (volume flow curve). A control group consisting of 10 individuals was studied adjacently. The study was performed within the pollen season. The determination of Raw value was carried out through increasing doses of histamine challenge employing the Apta-Jaeger apparatus. The results were expressed in PC20 wherein 26% of the pollen-affected patients presented bronchial hyperreactivity (positive histamine bronchial provocation test). In this group the values of basal Raw were found to be increased with respect to the control group (p less than 0.025) and pollen-sensitive patients with negative histamine bronchial provocation test (p less than 0.01). On the other hand, the pollen-sensitive group with negative response to histamine bronchial challenge presented Raw values which were similar to the control group.

Adult↗
PubMedDate not supplied

Local and serum IgE in patients affected by otitis media with effusion.

Various mechanisms intervene in the etiopathogenesis of otitis media with effusion (OME), but to date it is not clear which mechanism is the most important. We studied twenty children affected with persistent otitis media with effusion (OME) inspite of the indicated treatments, and the possible incidence of atopic features, total serum IgE and in effusion, obtained by myringotomy and aspiration were evaluated. In order to evaluate the presence of atopy, an allergic history and skin tests against the different suspected allergens (inhalants and foods) were realized.

Child↗
PubMedDate not supplied

Immunotherapy with a standardized Dermatophagoides pteronyssinus glutaraldehyde-modified extract against an unmodified extract: a comparative study of efficacy, tolerance and in vivo and in vitro modification of parameters.

We comparatively studied clinical efficacy, tolerance and modifications of different in vivo and in vitro parameters induced by two biologically standardized Dermatophagoides pteronyssinus extracts (HEP units), one glutaraldehyde-modified, in patients with allergic rhinitis and/or bronchial asthma after a year of treatment. A decrease in drug consumption was observed in both treatment groups (p < 0.0001). Of all the in vivo parameters studied (cutaneous, conjunctival and bronchial reactivity to the allergen), a decrease in specific bronchial reactivity was only observed in the group treated with the modified extract (p < 0.05). The modifications in total IgE, specific IgE and specific total IgG levels are superimposable on those described in previous papers on immunotherapy. However, IgG4 levels remained stable with respect to time. Tolerance was good and very similar for both treatments; both types of extracts are equally efficacious and safe.

Adolescent↗
PubMedDate not supplied

Indoor allergens and dwelling characteristics in two cities in Spain.

BACKGROUND: Indoor allergens are common causes of sensitization and asthma. Climatic and home conditions can modify their levels. OBJECTIVE: We studied the influence of climatic conditions and home characteristics on the exposure to indoor allergens of mite allergic asthmatic subjects in two Spanish cities with different climates (Las Palmas and Pamplona). METHODS: We included 65 subjects diagnosed with asthma caused by Dermatophagoides pteronyssinus. A questionnaire about their dwellings was completed. Home dust samples were collected. Mite (Der p1, Der f1, Der 2) and cat (Fel d1) allergens were measured by a monoclonal-antibodies based ELISA. RESULTS: Characteristics of dwellings were similar in both areas. Der p1 was the main allergen (0-44 micrograms/g). Der p1, Der f1 and Der 2 levels were higher in the homes in Las Palmas (p < 0.001, p < 0.01 and p < 0.001, respectively). Damp homes in Pamplona had higher Der p1 levels, similar to those detected in homes in Las Palmas. Fel d1 levels (0-78.90 micrograms/g) were only related to the presence of cats in the dwelling (p < 0.001). CONCLUSIONS: D. pteronyssinus allergen exposure was influenced by climatic conditions and dampness in homes in temperate regions. Humidity in homes can generate an ideal environment for mite growth despite unfavorable outdoor climatic conditions. Fel d1 levels were only related to the presence of a cat in the house.

Air Pollution, Indoor↗
PubMedDate not supplied

Reactive airways dysfunction syndrome: two case reports.

Reactive airways dysfunction syndrome (RADS) is a type of asthma that develops in subjects without prior pulmonary disease, following single or multiple exposure to high levels of nonimmunogenic irritants. The main difference from classic occupational asthma is the absence of a latency period. Non-specific bronchial hyperresponsiveness is characteristic of the disease and usually persists after cessation of exposure. We report the cases of two subjects in whom RADS developed after occupational exposure to irritants.

Adult↗
PubMedDate not supplied

Occupational allergic contact dermatitis due to airborne spiramycin.

We report the case of a man who worked in a feed factory. He developed allergic contact dermatitis due to airborne spiramycin, a commonly used antibiotic in veterinary medicine. The patient suffered recurrent outbreaks of eczematous lesions on uncovered areas during working periods. Diagnosis was made based on history, positive patch tests to spiramycin and to some feed compounds containing spiramycin, and on disappearance of lesions on leaving the work place.

Air Pollutants, Occupational↗