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Biomedical subjects

F de Blay

Publications and source records attributed to F de Blay.

At least 55 records · Page 3Linked to original sources
PubMed1995

Systemic sarcoidosis initially presenting as an orbital tumour.

A 73 year old woman presented with redness, itching and painless proptosis of the left eye. Clinical examination and computed tomographic (CT) scan of the orbit revealed a postero-ocular mass, the biopsy of which showed a noncaseating, giant cellular, epithelioid granuloma compatible with sarcoidosis. The patient had no respiratory complaints, but the thoracic CT scan showed multiple bilateral hilar and mediastinal adenopathies. Gallium scan showed increased uptake in both hilar regions, in the left orbit and in the right parotid gland. Multiple bronchial biopsies revealed sarcoid granulomas, with a bronchoalveolar lavage (BAL) cytological pattern of active sarcoidosis. The evolution was favourable with prednisolone given at a dose of 0.5 mg.kg-1 daily. It is suggested that in an unusual presentation of sarcoidosis, a thorough search should be made for localization at other sites, lungs in particular, even in the absence of respiratory complaints.

Aged↗
PubMed1995

[Importance of measuring exposure to the principal indoor allergens in allergic asthma].

Domestic allergens, such as mite and cat allergens, are a leading cause of allergic asthma. Allergen exposure is a risk factor for sensitization. Allergens also play a major role in the development of inflammation and non specific bronchial hyperreactivity as well as in the apparition and modulation of symptomatic asthma. The development of new means of detecting allergens (i.e. immunochemical assays including monoclonal antibodies, quantitative and semiquantitative guanine measurements for mite allergens) has made possible to identify allergens sources and reservoirs. The form in which domestic allergens become airborne is important. The group I and II allergens from mites, the major cockroach allergens are carried on large particles (mean size > 10 microns diameter); in contrast, the major cat allergens are airborne on small particles (40% < 5 microns). Guanine, a metabolic excretion product of mites, is used as a marker for mite feces and is correlated with the presence of major allergens from mites. A colorimetric method (Acarex-TestR) provides a simple and inexpensive method of assaying indoor mite allergen exposure for both doctor and patient alike. By using Acarex-TestR it is possible to evaluate the mite allergen exposure for a population in a particular country. The detection of allergens sources and reservoirs, the quantification of domestic allergens has enabled the evaluation of the effect of a reduction in allergen exposure to be better assessed. Recognition of the risks, environmental control and reduction in allergen loads, should be among the objectives of asthma management.

Air Pollution, Indoor↗
PubMed1994

Minocycline pneumonitis and eosinophilia. A report on eight patients.

We identified eight patients (six women and two men) who had pulmonary infiltrates during treatment with minocycline hydrochloride between 1989 and 1992 in French referral centers for drug-induced pulmonary diseases. Clinical files, chest roentgenograms, computed tomographic scans, pulmonary function, and bronchoalveolar lavage data were reviewed. Minocycline treatment was given for acne (n = 4), genital infection (n = 3), and Lyme disease (n = 1). The duration of treatment averaged 13 +/- 5 days (mean +/- SE); the total dose, 2060 +/- 540 mg. Patients presented with dyspnea (n = 8), fever (n = 7), dry cough (n = 5), hemoptysis (n = 1), chest pain (n = 2), fatigue (n = 3), and rash (n = 3). Chest roentgenograms showed bilateral infiltrates in all cases. Pulmonary function was measured in five patients; four had airflow obstruction and two had mild restriction. Blood gas tests demonstrated hypoxemia in seven patients (58 +/- 3 mmHg). Seven patients had blood eosinophilia (1.76 +/- 0.2 x 10(9)/L). Bronchoalveolar lavage (performed in seven patients) showed an increased proportion of eosinophils (0.30 +/- 0.07). The Cd4+/CD8+ ratio was determined in four cases and was low in three. Transbronchial lung biopsy, performed in two patients, showed interstitial pneumonitis in both patients, with marked infiltration by eosinophils in one patient. The outcome was favorable in all patients. Because of severe symptoms, steroid therapy was required in three patients. Rechallenge was not attempted. We conclude that minocycline can induce the syndrome of pulmonary infiltrates and eosinophilia, that presenting symptoms may be severe and may culminate in transient respiratory failure, and that the disease has a favorable prognosis.

Adolescent↗
PubMed1994

From allergen sources to reduction of allergen exposure.

Allergen exposure plays a major role in the development of sensitization, inflammation and symptomatic asthma. The development of new means of detecting allergens has enabled the evaluation of the effect of a reduction in allergen exposure to be better assessed. In order to prevent allergen exposure it is necessary to determine the allergen sources and reservoirs to which avoidance measures should be directed. The allergen sources and reservoirs of mite, cat, dog, cockroach, rodent, mould and pollen allergens are briefly reviewed. The relationships between allergen exposure, sensitization, nonspecific bronchial hyperreactivity and asthma symptoms are discussed. Recognition of the risks, environmental control, and reduction in allergen loads should be among the objectives of asthma management.

Allergens↗
PubMed1993

Receiver operating characteristic analysis: a useful method for a comparison of the clinical relevance of two in vitro IgE tests.

BACKGROUND: The objectives of this study were to demonstrate the usefulness of Receiver Operating Characteristic (ROC) analysis in the definition of a positive threshold in the comparison of two in vitro tests for detecting IgE antibodies and to determine the clinical relevance of specific IgE tests according to the sensitivity and specificity determined by ROC analysis. METHODS: Specific IgE levels were compared with the use of both MATRIX (Abbott Laboratories, Chicago, Ill.) and PHADEZYM (Pharmacia, Uppsala, Sweden) tests in 109 patients: 86 allergic patients and 23 control subjects. All allergic patients had a clinical history of allergy to mite, cat, grass pollen, or birch pollen and positive skin prick test results to the suspected allergen. Using various levels of specific IgE, we determined the points of the ROC curves with the best ratio of true positives to false positives for four aeroallergens (i.e., mite, cat, grass pollen, and birch pollen). RESULTS: Except for mite allergen there was no correspondence between the positive threshold values determined by ROC analysis with MATRIX and PHADEZYM tests. In terms of class, when ROC analysis was used, the threshold was class III with the MATRIX test and class II with PHADEZYM test for cat, grass pollen, and birch pollen and class III for mite. According to the threshold value, sensitivity and specificity for MATRIX and PHADEZYM tests were similar except for cat, for which the PHADEZYM test had a lower sensitivity (0.71) than the MATRIX test (0.90). With mite allergen the predictive value of only one positive MATRIX test result was 0.96. The specificities of MATRIX and PHADEZYM tests were 100% in both nonatopic and atopic control groups. CONCLUSIONS: We conclude that ROC analysis is a reliable method for comparing IgE in vitro tests and that it emphasizes the lack of correspondence between arbitrary units given for each in vitro test. ROC analysis appears to be a good method for helping to standardize IgE in vitro tests.

Adult↗
PubMed1993

The effect of vacuum cleaners on the concentration and particle size distribution of airborne cat allergen.

BACKGROUND: Vacuum cleaners are essential for the removal of dust from the surface of carpets; however, they may also contribute to airborne dust both by leakage through the cleaner and disturbance of floor dust. METHODS: The present studies used established techniques for measuring airborne Fel d I to study the effects of vacuum cleaners on airborne cat allergen under laboratory conditions and in houses with cats. Nine different models were loaded with dust containing 50 mg Fel d I and run for 15 minutes in a laboratory room (volume approximately 18 m3). Leakage was expressed as the airborne concentration of allergen in nanograms per cubic meter. RESULTS: Cleaners incorporating a double-thickness dust bag either did not leak, that is, less than 0.4 ng Fel d I/m3 or had minor leakage approximately 5 ng/m3. Vacuum cleaners with single-thickness paper bags leaked more, that is, 15 to > 90 ng/m3 with the exception of the cleaner with an efficient outer bag. Detailed studies on a vacuum cleaner that leaked showed that placing dust in the bag, replacing the dust bag with a double-thickness bag, and placing an electrostatic filter over the exhaust reduced levels from greater than 90 ng/m3 to less than 2 ng/m3. Two water-filter vacuum cleaners each emitted cat allergen (up to > 100 ng/m3) with a mean of approximately 90% on particles less than 2.5 microns diameter. This emission could be almost completely controlled by taping electrostatic filter paper over the air outlet. CONCLUSIONS: In houses with cats, different models of vacuum cleaners could either reduce or increase total airborne allergen, and could also selectively increase certain particle sizes. These results suggest that cat allergen is a good model for studying the effectiveness of vacuum cleaners recommended to allergic patients.

Air Pollution, Indoor↗
PubMed1993

Mite-allergen exposure and spontaneous histamine release in monosensitive and polysensitive mite-allergic patients.

Forty-three patients allergic to mites and suffering mainly from asthma were recruited: 25 were mite-monosensitive and 18 were polysensitive, as determined by skin tests and specific serum IgE determinations with various allergens. In vitro spontaneous histamine release (SHR) by washed blood basophils was measured once or several times for each patient. Throughout this study, the mean periods of high and low mite-allergen exposure were defined on the basis of relative indoor humidity and temperature data. For the mite-monosensitive patients, there was a significant increase in mean SHR during the season of high mite-allergen exposure as compared to the months of lower mite-allergen presence (P < 0.002). No significant difference between mean SHR values was observed when comparing the monosensitive group during the season of high mite-allergen exposure with polysensitive patients (allergic to mite and pollen) during the period of exposure to both allergens. Differences in mean SHR reported here emphasize the positive relationship between intense allergen exposure and the in vitro SHR increase in blood basophils of mite-allergic patients.

Adult↗
PubMed1993

[Prevention of asthma caused by dust mites].

The house-dust mites are responsible for the majority of allergic asthma. It is currently possible to measure the exposure to their allergens, and this allows for a better guide as to the indications for eviction measures; there is also a more objective appreciation of the efficacy of these measures. A decrease in the relative humidity of the interior of the house effectively hinders the proliferation of the mites. Vacuuming the room, notably the mattress, is not sufficient in the majority of cases to reduce the level of allergenicity of the mites to a tolerable level for the asthmatic patient. Thus, it is necessary to renew the bedding, or to hermetically seal the mattress in a plastic cover. Washing the bedding at a temperature above 55 degrees C will kill the mites. Amongst the chemicals available in the struggle to reduce the mite population, the acaricides lead to an elimination of 65-100% of the mites in a mite culture. Tannic acid, which is a protein de-naturing agent, can reduce the allergenicity of the house-dust. Certain control studies related to the effect of the acaricides demonstrate an improvement in objective and subjective parameters of both asthma and rhinitis due to mites. However, the efficacy of these acaricides, as well as measures to clean up the environment within the house, merit more precise evaluation on the symptomatology, the changes of expiratory flow rates, and finally of broncho-reactivity in patients. It is probable that several preventative measures need to be associated if one wishes to improve the efficacy of the struggle to control the house-dust mites.

Animals↗
PubMed1992

Cat allergy.

Explore the source record for details and available documents.

Allergens↗
PubMed1991

Airborne dust mite allergens: comparison of group II allergens with group I mite allergen and cat-allergen Fel d I.

The form in which allergens become airborne is important because it may influence both symptoms caused by allergen exposure and methods used to reduce exposure. The group I allergens from dust mites only become airborne during disturbance and fall rapidly, which is in keeping with their being carried on fecal pellets. Their mean size is approximately 20 microns in diameter. By contrast, the cat-allergen Fel d I is airborne on particles varying from greater than 10 to less than 2 microns in diameter, some of which remain airborne even without disturbance. A second group of mite allergens, molecular weight 14,000, are equally important and are associated predominantly with mite bodies. With a monoclonal antibody-based assay and a cascade impactor, we have investigated the form in which group II mite allergens become airborne. The results reveal that these allergens only become airborne during disturbance and that they fall within 15 minutes. However, the mean size of particles carrying group II allergens appears to be slightly smaller than the mean size of particles carrying group I allergens. In addition, the quantities of group II allergen becoming airborne during disturbance (mean, 26 ng/m3) could not be explained by the quantity found in fecal particles. Thus, group II mite allergens become airborne in a form quite distinct from cat allergens and very similar to group I mite allergens; however, it appears unlikely that fecal particles are the main form in which group II allergens become airborne.

Allergens↗
PubMed1991

Airborne cat allergen (Fel d I). Environmental control with the cat in situ.

In a house with a cat furnishings, air-exchange rate, and the cat are all thought to influence airborne cat allergen. We carried out experiments using two separate rooms, modifying the environment, applying different cleaning techniques, and washing the cat, to analyze these sources and to design methods of reducing airborne allergen. Airborne measurements were made with a cascade impactor and a two-site monoclonal antibody-based immunometric assay for cat allergen Fel d I. Within 30 min of entering a 30-m3 clean room the cat itself was found to increase airborne Fel d I by 30 to 90 ng/m3. Following serial weekly washing of the cat this increase was reduced to less than or equal to 7 ng/m3, with a more marked fall in small particles (less than or equal to 2.5 microns diameter) from 9.5 to less than or equal to 0.4 ng/m3. To study the influence of the room design we kept the cat in a room of 33 m3 for 20 h/day and modified the room. This room was studied with or without furnishings and with air-exchange rates of 0.2 or 2.4 air changes per hour. Both low ventilation rate and furnishings increased the level of Fel d I measured 1 h after the cat was removed. However, the most striking finding was that the carpet accumulates cat allergen at approximately 100 times the level for a polished floor, that is, approximately 100 micrograms/day Fel d I compared with approximately 0.5 micrograms/day Fel d I.(ABSTRACT TRUNCATED AT 250 WORDS)

Air↗