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Biomedical subjects

F Beaumont

Publications and source records attributed to F Beaumont.

27 records · Page 2Linked to original sources
PubMed1984

Immunologic studies in bronchoalveolar fluid in a patient with allergic bronchopulmonary aspergillosis.

Bronchoalveolar lavage was performed in a patient during an acute stage of allergic bronchopulmonary aspergillosis (ABPA) and repeated 17 mo later during a remission stage and cessation of corticosteroid therapy. Measurement of protein concentrations (albumin, IgG, IgA, and IgM) by laser nephelometry and crossed immunoelectrophoresis indicates that transudation of proteins occurs from the circulation into the lung compartment during the acute stage of ABPA. Furthermore, comparing total Ig concentrations and titers of ELISA IgG, IgA, and IgM antibodies against Aspergillus fumigatus with the corresponding values of serum measurements indicates a preferential local production of IgA antibodies and IgM to a lesser extent. No indications were found for a local production of either IgG, total IgE, or IgE against A. fumigatus. During remission of the ABPA, titers of antibodies in the bronchoalveolar fluid (BAF) decreased to normal levels except IgA against A. fumigatus that remained elevated. The elevated titers of IgA in the BAF and IgE antibodies in the serum against A. fumigatus together with the elevated numbers of granulocytes in the BAF during the remission stage indicate that the immunologic situation is not yet normalized.

Antibodies, Anti-Idiotypic↗
PubMed1984

Immunologic observations in sera of a patient with allergic bronchopulmonary aspergillosis by means of the enzyme-linked immunosorbent assay.

Titers of IgG, IgA, and IgM antibodies against Aspergillus fumigatus were measured by ELISA in sera of a patient with allergic bronchopulmonary aspergillosis during an acute stage, remission, and exacerbation of the disease. Total IgE, specific IgE against A. fumigatus, and number of precipitation lines were also measured. ELISA IgG-, IgA-, and IgM-antibody titers were expressed in percentages of the titer of a strongly positive standard serum by use of the patient's own serum as a standard. The fall in antibody concentration (in percent) and elevations during exacerbation appeared to be similar for these antibody classes and are related with the number of precipitates measured by double immunodiffusion. Furthermore, the changes in antibody titers were also similar to the elevations and decreases in both total IgE and specific-IgE antibodies (also expressed in percentages of a chosen standard serum). The ELISA IgG-antibody titers were higher compared with the ELISA IgA or IgM titers and demonstrated a continuous decline during a period of 2 yr after the acute phase of ABPA. Therefore, IgG-antibody titers are preferred as an indicator of disease activity in follow-up studies over longer time periods and are at least as sensitive as the measurement of concentrations of IgE antibodies.

Adult↗
PubMed1984

The allergenic and antigenic properties of spore extracts of Aspergillus fumigatus: a comparative study of spore extracts with mycelium and culture filtrate extracts.

The antigenic properties of conidial preparations of Aspergillus fumigatus were compared with mycelial and culture filtrate extracts by use of sera of patients with aspergillosis and hyperimmune rabbit serum. Biologic activities were tested by intracutaneous tests. The immunologic parameters used were: precipitating properties in double-diffusion, IgG binding by ELISA, IgE binding by enzyme inhibition assay, and by enzyme allergosorbent test. It has been demonstrated that the components that are released after disintegration of spores have positive titers in all immunologic assays. The immunologic properties of these spore plasma extracts are comparable with mycelial and/or culture filtrate extracts that are in accordance with the corresponding skin reactivities. Components that are released spontaneously from spores are only weakly positive or negative in the immunologic assays and demonstrate a very low biologic activity.

Allergens↗
PubMed1984

Environmental aerobiological studies in allergic bronchopulmonary aspergillosis.

An aerobiological pilot study was undertaken to measure airborne concentrations of Aspergillus spores in and around the dwellings of two patients with allergic bronchopulmonary aspergillosis (ABPA). The aim of the investigation was 1) to find a specific source of Aspergillus antigen, and 2) to find out whether disease activity, or exacerbation, paralleled Aspergillus spore prevalence. In the environment of the first patient heavy spore contaminated air was found in a cow-shed, and the adjacent hayloft and scullery. The patient experienced no typical exacerbation during the study period, probably because she now scrupulously avoided this source. The environment of the second patient contained lower spore concentrations in and around the house, and the patient had no typical exacerbation, possibly due to low-intensity exposure. Both patients, however, had increased bronchial obstruction during periods with high Aspergillus spore content in the outside air. The results suggest that avoidance of Aspergillus spore sources and low overall exposure may play a major role in preventing exacerbation of the disease.

Adult↗
PubMed1984

A volumetric-aerobiologic study of seasonal fungus prevalence inside and outside dwellings of asthmatic patients living in northeast Netherlands.

Air sampling with an Andersen sampler was carried out over a period of 21 mo, in 28 houses of asthmatic patients with an allergy for moulds. Inside, the livingroom, bedroom, and kitchen were studied, and an additional outside sample was always taken. Indoors, Penicillium showed the highest concentration, especially in the autumn and winter months, while Aspergillus and yeasts were also found frequently. The outside air was dominated by Cladosporium and Alternaria during summer months and Botrytis, Aspergillus, Mycelia sterilia and Basidiomycetes all year round. The patients showed high sensitisation towards Aspergillus, irrespective of the concentrations of the airborne fungi.

Alternaria↗
PubMed1983

Comparison of antibody measurements against Aspergillus fumigatus by means of double-diffusion and enzyme-linked immunosorbent assay (ELISA).

IgG antibody titers against Aspergillus fumigatus from different sera were measured by means of a standardized ELISA and compared with precipitates measured by double diffusion (D.D.). There was a significant correlation between the number of precipitates and the ELISA IgG titers in the 758 sera examined. However, in several individual sera within this group, large deviations between these two immunologic parameters were found. Further analysis indicated that ELISA detects antibodies against nonprecipitating antigenic components in addition to the antibodies detected by D.D. Furthermore, not all precipitating antigenic components appear to play a role in the detection of antibodies against A. fumigatus by ELISA. Patients with aspergillosis largely show increased titers of IgG antibody by ELISA even when the results of D.D. are negative, except those of patients with Aspergillus-provoked asthma which fall within a normal range.

Alveolitis, Extrinsic Allergic↗
PubMed1981

Simultaneous occurrence of pulmonary interstitial fibrosis and alveolar cell carcinoma in one family.

The coexistence of interstitial pulmonary fibrosis and alveolar cell carcinoma is well known. The familial occurrence of a combination of these two entities, however, is very rare. We present a family of which five members had diffuse interstitial pulmonary fibrosis. Three of them had in addition alveolar cell carcinoma. In a sixth family member, evidence of alveolar cell carcinoma was present without proven interstitial fibrosis. An autosomal dominant trait is suggested as the mode of inheritance of both interstitial fibrosis and alveolar cell carcinoma in this family.

Adenocarcinoma, Bronchiolo-Alveolar↗
PubMedDate not supplied

A new photoconductor imaging system for digital radiography.

Amorphous selenium is a material often used in the x-ray imaging system. The main application is in xeroradiography where the structure of the sensor is a layer of selenium on a conductive substrate. The signal is a charge density on the surface which is revealed by a toner or by electrostatic probe for digitalization. In the system described here, the sensor structure is different for the sensor is covered by an electrode, a thin layer of metal, which gives another interface. The reading system needs the scanning of a light beam and the resolution power depends on the size of the beam. It is easier to scan a light beam than electrostatic probes so a more compact system can be realized. In the process, there are two phases: the storage and the reading. The time spent between the two phases reduces the quality of the image, and an in situ reading system, integrated to the radiographic machine will be, for this reason, more efficient. Also, the sensor needs good memory effect. One has investigated different sensors based on a structure of a thin photoconductive layer between two electrodes to find a memory effect. We have already seen this phenomena in the Bi12 SiO20 (B. Richard, "Contribution à l'étude d'un procédé d'imagerie radiologique utilisant le photoconducteur BO12 SiO20," Ph.D. thesis, Paris, 1987). In amorphous selenium with some dopants and some type of metallic contact, the memory effect is important enough to realize a system. With 2 X 2 cm samples, a complete x-ray digital imaging system has been built.(ABSTRACT TRUNCATED AT 250 WORDS)

Electric Conductivity↗