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Biomedical subjects

S Quirce

Publications and source records attributed to S Quirce.

At least 55 records · Page 3Linked to original sources
PubMed1996

In vitro T-lymphocyte response and house dust mite-induced bronchoconstriction.

BACKGROUND: There is considerable evidence that T cells may play an important role in asthma. The purpose of this study was to determine whether the responsiveness of T lymphocytes to mite allergen stimulation in vitro is a determinant of bronchial response to house dust mite (HDM) allergen challenge in subjects who are allergic to HDM. METHODS: Peripheral blood was taken from seven healthy nonatopic subjects and 23 subjects with positive skin test reactions to HDM. Of the subjects in the latter group, 16 had an asthmatic reaction on inhalation challenge with HDM extract (HDM-responders), whereas the remaining seven had a negative reaction (HDM allergic). The proportion of subsets of T lymphocytes and their activation and the amount of IL-2, IL-4, IL-5, and interferon-gamma released in the supernatants with and without stimulation with the HDM extract were determined. RESULTS: Without stimulation, the proportions of subsets of T lymphocytes and their activation were similar between groups. When stimulated with the HDM allergen, the proportion of CD4+CD25+ cells from HDM responders was significantly higher than those in the control group. Comparison within groups of cell cultures with and without stimulation with the mite allergen showed that the proportion of CD4+, CD4+CD25+, CD4+/CD8+, and CD3+HLADR+ cells were significantly increased in HDM responders with stimulation; there was a trend for CD4+CD25+ cells to be increased in the HDM-allergic subjects; no increase in any T-lymphocyte subsets was found in the control subjects. The release of IL-5 was significantly greater in HDM responsers than in the other two groups. The severity of the immediate asthmatic reaction was significantly associated with the degree of nonallergic bronchial hyperresponsiveness and the amount of IL-5 released but not with the level of specific IgE to the mite allergen or subsets of T lymphocytes with and without stimulation. CONCLUSION: The findings suggest that responsiveness of T lymphocytes to allergen challenge in vitro may play a role in determining the bronchial response to the allergen in vivo.

Animals↗
PubMed1996

Diversity of allergens causing occupational asthma among cereal workers as demonstrated by exposure procedures.

BACKGROUND: Occupational asthma among cereal workers is frequently due to cereals but other allergens can also be responsible. OBJECTIVE: We evaluated the allergens causing occupational asthma in the patients who had been diagnosed in our Department during the last 5 years. Specific bronchial reactivity to the implicated allergens was assessed and compared by standardized bronchial challenge. METHODS: Twenty-one patients (12 bakers, three millers and six farmers) were studied. We carried out in vivo tests (skin and challenge tests) and in vitro tests (specific IgE measurement) with cereals, enzymes, soyabean, storage mites and egg. A definitive diagnosis was established by means of specific bronchial provocation tests (BPT), except in three patients in whom it could not be carried out due to the severity of their asthma. In these cases the causative agent had to be determined by means of conjunctival challenge. RESULTS: Cereals were the main sensitizers among bakers (75%) and farmers (66%). Bakers were also sensitive to alpha-amylase (41%) and soyabean (25%), and farmers, to soyabean (33%) and storage mites (33%). Occupational asthma was due to cereals, soyabean and storage mites among millers. CONCLUSIONS: Besides cereals, other allergens such as enzymes, leguminous, egg and storage mites can be the causative agents of occupational asthma among cereal workers. Sensitization to different allergens in the different jobs is very likely due to differences in exposure.

Adult↗
PubMed1995

Pickled onion-induced asthma: a model of sulfite-sensitive asthma?

BACKGROUND: Asthma elicited by sulfite ingestion has been mainly described in steroid-dependent and in non-atopic asthmatics. We have studied a group of 18 young extrinsic asthmatics who presented with asthma attacks immediately after eating pickled onions. OBJECTIVE: The aim of this study is to ascertain if these asthma attacks are elicited by sulfites contained in pickled onions and the influence of the dose and pH of onions. METHODS: The bronchial hyperreactivity of the patients was assessed by a methacholine challenge test. Oral challenge tests were performed with sodium metabisulfite (MSB) diluted in lemon juice at pH 4.2 and at pH 3.3 (only in patients who did not react with pH 4.2). Two types of pickled onions, Spanish and Dutch pickled onions, were used for oral challenge in seven of the patients. The Monier-Williams method was used to measure the SO2 concentration in pickled onions. RESULTS: The oral provocation test with MBS, pH 4.2, elicited a positive response in six patients (33.3%) and the test at pH 3.3 was positive in three out of 12. No significant difference in PD20 values was found between these groups. Three of the seven patients challenged with Spanish pickled onions had a positive reaction but had no reaction with Dutch pickled onions. The SO2 concentration in Spanish pickled onions varied between 765 and 1182 ppm while in Dutch pickled onions were 200 ppm; this exceeded the permitted level (100 ppm). SO2 release in Spanish pickled onion samples was nearly 2.5 times higher when the pH of the sample decreased from 4.2 to 3.3. CONCLUSION: High levels of SO2 in Spanish pickled onions, and their low pH (3.3) would be the responsible factors of the asthmatic outbreaks after ingestion of Spanish pickled onions by these patients.

Adolescent↗
PubMed1995

Peak expiratory flow monitoring is not a reliable method for establishing the diagnosis of occupational asthma.

This is a study of the reliability of peak expiratory flow (PEF) monitoring using a portable computerized peak flow meter, the VMX Mini-log, in 17 subjects referred for suspected occupational asthma. Subjects were requested to monitor their PEF six times daily using the VMX Mini-Log for 2 wk at work and at least 10 d away from work. They were unaware that their readings were stored by the flow meter in addition to the digital readout. Four subjects (22%) were unable to complete the monitoring. The results recorded by the subjects were compared with the results recorded by the VMX. Of those who completed the monitoring, only 55.3% of the records were completely accurate in terms of the value and the timing of the measurements, 23.3% were inaccurate either in terms of the recorded value or of the timing of the measurement, and the remainder were fabricated results (not recorded by the Mini-Log). Our results suggest that PEF monitoring using ordinary peak flow meters for assessment of work-relatedness of asthma has limitations and is not reliable.

Adult↗
PubMed1995

Major cat allergen (Fel d I) levels in the homes of patients with asthma and their relationship to sensitization to cat dander.

BACKGROUND: Exposure and sensitization to the major cat allergen, Felis domesticus allergen I (Fel d I), significant causes of allergic respiratory disease. Many patients who are allergic to cats, however, do not own a cat and there is not an obvious source of allergen in their home environment. OBJECTIVE: We investigated the levels of Fel d I in dust from homes of 120 subjects with asthma in two climatologically diverse Canadian cities (Vancouver and Winnipeg). Fel d I levels were related to exposure to cats as well as to skin reactivity to cat dander. METHODS: Dust samples from bedroom floors and mattresses were collected in four different seasons and Fel d I content was determined by 2-site monoclonal antibody based-ELISA. RESULTS: Although only 18 patients (15%) were cat owners, detectable levels of Fel d I were found on at least one occasion in all homes. The geometric mean concentration of Fel d I on floors was 1.15 micrograms/g of dust (range 0.07 to 26.3 micrograms/g) and on mattresses 0.89 micrograms/g (range 0.01 to 17.4 micrograms/g). Seasonal variation of Fel d I levels was only observed in Winnipeg, where Fel d I concentrations were highest in the winter and spring compared with either summer (P < .05) or autumn (P < .005). The highest Fel d I levels were found in homes with a cat (P < .05), however, rather high levels were also found in homes of patients who did not have a cat but visited others with cats. Cat dander was the most frequent sensitizer (60%) in these patients but no correlation was found between the size of the wheal induced by cat dander extract and Fel d I levels in dust samples. CONCLUSION: Cat allergen was universally found in homes of asthmatic patients and this may explain the high frequency of cat sensitization among patients with asthma in these two cities. A seasonal variation in cat allergen was observed in Winnipeg with no variation in Vancouver.

Adolescent↗
PubMed1994

Green bean hypersensitivity: an occupational allergy in a homemaker.

As a member of the legume family, the green bean is frequently associated with food allergy. However, allergic reactions caused by skin contact or by inhalation of vapors from boiling legumes are rare. This article presents a case of occupational asthma in a homemaker; symptoms occurred during preparation and cooking of raw green beans. Skin prick, rub, and bronchial provocation tests were performed on the patient. In vitro tests were done with the serum samples of the patient and 10 control subjects (5 atopic and 5 nonatopic). Test results indicate that the patient has type I hypersensitivity to raw green bean antigen(s). This case is of interest because it demonstrates that a food allergen, when inhaled, can induce respiratory symptoms in sensitized patients and may even be the source of primary sensitization.

Adult↗
PubMed1994

Occupational asthma and immunologic responses induced by inhaled carmine among employees at a factory making natural dyes.

Carmine is a natural red dye widely used as a food coloring agent and for cosmetic manufacture. It is extracted from the dried females of the insect Dactylopius coccus var. Costa (cochineal). Although it has been reported that inhalation of carmine may give rise to occupational asthma and extrinsic allergic alveolitis, there is little evidence of its immunogenic capacity. We studied nine current employees at a factory making natural dyes and one former employee who had left this plant after occupational asthma developed. A current employee had work-related symptoms of rhinitis and asthma that were confirmed by bronchial provocation tests, and another worker had rhinitis. Immunologic sensitization to carmine and cochineal was evaluated by means of skin testing and determination of serum-specific IgE and IgG subclass antibodies by RAST and ELISA, respectively. The specificity of the RAST assay was investigated by RAST inhibition with different fractions of carmine. The three workers with respiratory symptoms had positive skin prick test reactions to both carmine and cochineal. An immediate response to the bronchial provocation test with carmine and cochineal was observed in the current employee with asthma. Specific IgE antibodies against carmine and cochineal were found only in this worker. RAST inhibition studies indicated that the main allergen had a molecular weight between 10 and 30 kd. Specific IgG antibodies against carmine and cochineal, mainly the subclasses IgG1, IgG3, and IgG4, were found in the 10 subjects surveyed. These findings suggest that carmine may induce immunologic responses, most likely IgE mediated in workers with symptoms of occupational asthma.

Adolescent↗
PubMed1994

Asthma and contact urticaria caused by rice in a housewife.

We report the case of an atopic housewife who presented with rhinoconjunctivitis-asthma and contact urticaria from handling rice and other cereals. She tolerated cooke cereals. Both skin prick tests with a rice extract (20% w/v) and a rub test with raw rice gave positive results. Bronchial challenge test with methacholine revealed a PC20 of 0.45 mg/ml. The challenge test with raw rice resulted in immediate and late clinical and spirometric responses; pretreatment with DSCG inhibited both responses. The histamine release test (HRT) with rice was positive, and we detected rice-specific IgE antibodies by REIA in the patient's serum. Skin prick tests, HRT, and RAST with a battery of cereals gave positive results. Finally, the rice REIA was inhibited by rice (75%), rye (63%), corn (64%), and wheat (51%) extracts.

Adult↗
PubMed1994

Airborne contact dermatitis from Frullania.

7 subjects, each giving a history of scaly or vesicular dermatitis in light-exposed areas after going for strolls to the park, the forest or the country during warm weather, were evaluated. Patch testing was carried out with Frullania dilatata and Frullania tamarisci as well as with 2 common members of the Compositae and to alantolactone and the sesquiterpene lactone mix. All the patients were positive to F. dilatata, 3 reacted to F. tamarisci as well, and 2 to florists' chrysanthemum. All of them except 1 gave positive responses to the sesquiterpene lactone mix, but only 3 reacted to alantolactone. Airborne contact dermatitis from these species of Frullania was considered to be the cause of their eczema. Patch testing with the sesquiterpene lactone mix seems to be a good screen for Frullania sensitivity; however, a variable pattern of response to these sesquiterpene-lactone-containing materials was observed, suggesting individual immunologic responses to them.

Adult↗
PubMed1993

Occupational asthma and contact urticaria from dried flowers of Limonium tataricum.

Dried flowers of Limonium tataricum (LT) are widely used for semipermanent floral arrangements. We report a case of a floral industry worker in whom exposure to LT precipitated rhinoconjunctivitis, asthma, and contact urticaria. Studies revealed the presence of immediate skin test reactivity and positive leukocyte histamine release in response to LT extract. Specific anti-LT antibodies were detected in the patient's serum by direct RAST. Bronchial challenge with LT extract also resulted in an isolated immediate asthmatic response. Both the positive methacholine inhalation test and the significant changes observed in PEFR measurements when the patient handled LT supported the diagnosis of occupational asthma. These findings strongly suggest that an IgE-mediated immunologic mechanism is responsible for the patient's respiratory and cutaneous symptoms.

Adult↗
PubMed1993

A prospective safety-monitoring study of immunotherapy with biologically standardized extracts.

We evaluated the safety of immunotherapy in 419 patients who attended our allergy department for treatment. They were suffering from rhinitis and asthma caused by sensitization to grass pollen or Dermatophagoides pteronyssinus. Immunotherapy was given by biologically standardized aluminum hydroxide adsorbed extracts according to a conventional schedule. Local reactions were recorded in 10.5% of the patients and systemic reactions in 4.8%. Only 0.37% of the doses administered were associated with systemic side-effects. We found that 84% of the patients who showed systemic reactions were asthmatic subjects (P < 0.01), and most of them were sensitized to D. pteronyssinus (71%). Side-effects occurred more frequently during the dose-increase period (P < 0.05). After 9482 doses had been administered, no anaphylactic shock or life-threatening reactions were registered. We believe the risk associated with immunotherapy to be drastically reduced when treatment is carefully monitored by skilled personnel. In such conditions, as shown by our study, immunotherapy is safe.

Adult↗
PubMed1993

Cross-reactivity between quinolones. Report of three cases.

Cross-reactivity between quinolones is uncertain. Recently, we studied three patients who had developed suspected allergic reactions to a quinolone. For all of them we performed skin test, histamine release test, RAST, and oral provocation with the suspected quinolone and also with another quinolone of the opposite generation. Five atopic and five nonatopic subjects were used as controls. Neither skin test, histamine release test, nor RAST was useful in the diagnosis. By means of oral controlled provocation, the reactions were reproduced, and all the patients also reacted to another quinolone. We concluded that cross-reactivity between quinolones seems to be very important, and avoidance of any quinolone should be recommended to any patient who has suffered an allergic reaction to one of these drugs.

Adult↗