[Dust exposure, dust-induced lung diseases and respiratory protective measures in agriculture]

Epidemiologic studies indicate a high prevalence of respiratory diseases among the farming population. Many of these diseases are responsible for disability and death and there is a considerable impact on the economy and health cost expenditure. Respirable organic dust plays a major pathogenetic role. Part I of this review discusses the diseases and syndromes caused by organic dust: organic dust toxic syndrome; chronic bronchitis and chronic obstructive pulmonary disease; asthma; and hypersensitivity pneumonitis. Part II describes preventive measures for dust control. Besides technical aspects in the process of agriculture production, special emphasis is placed on personal protective equipment systems (face-masks and air-purifying respirators). Applications, advantages and disadvantages of these systems are discussed and critically compared.

[Early diagnosis and effective prevention of occupational allergies caused by hexavalent chromium]

Clinical and allergologic evaluation covered a large group of workers engaged into alumina production and exposed to chromate. Those workers were also subjected to long-standing follow-up. The studies helped to find correlation of chromium concentration in air with occurrence of the occupational allergies and latent sensibilization of respiratory tract to chromium. Immune modulator Levamisol was proved to act as a desensibilizer in prophylaxis of the occupational allergies in individuals with the latent sensibilization.

[Effectiveness of a test for verification of the presence of acari in house dust for the prevention of respiratory allergies in children]

Respiratory allergy and bronchial asthma in particular can be serious afflictions in younger as well as in older children. Therefore interest has been focused on methods for the prevention of atopy. The role and allergenic importance of Dermatophagoides pteronyssinus (Dpt) in house and other environments have been identified. This mite provokes asthma in children at an earlier age than pollens. However the most under-valued area of asthma prevention is environmental control. The steps may seem difficult at first, but the results will be well worth the efforts and the sacrifices. We report on the high effectiveness of the guanine detection test (Acarex) based on the colorimetric quantification of allergen sources in house dust (mattresses, pillows, upholstered furniture, carpets, moquettes, etc), which can be treated with house dust mite extermination products such as benzyl benzoate. The eradication measures will allow the parents to reduce the allergen exposure, to be monitored at 3-6 month intervals. The guanine detection test performed in our Division on house dust samples assembled by the patents of children with house dust mite induced asthma (study group) or pollen asthma (control group) yielded highly significant statistical differences.

[Epidemiologic aspects of allergic respiratory tract diseases]

There is no doubt today, that allergic diseases of the airways have a considerable genetic background. However it is also evident, that extrinsic factors are more or less responsible for the manifestation of these diseases. Epidemiological studies are an important tool to develop programs for effective prevention measurements. This is necessary to decrease the morbidity and with that also mortality. In principle allergic airway diseases have a very good prognostic outlook, since our present symptomatic therapy as well as the specific immunotherapy are very effective in treating these patients. Another aspect, which has to be considered, is the social economical factor, which signals, that increased mortality is to a great extend dependent on medical judgement and appropriate treatment, especially in the poorer patient population. Another reason for the increased mortality might be the inadequate education of therapists to deal with this type of disease.

Effect of an inhaled corticosteroid on airway eosinophils and allergen-induced airway hyperresponsiveness in dogs

The presence of airway eosinophils before allergen inhalation may contribute to the development of allergen-induced airway responses. We examined whether a reduction in airway eosinophil numbers before allergen inhalation as a result of inhalation of the corticosteroid budesonide would prevent allergen-induced airway hyperresponsiveness in seven dogs. Acetylcholine airway responsiveness was measured before and 24 h after inhalation of Ascaris suum allergen (10(-6)-10(-2) wt/vol) or its diluent on 4 test days separated by > or = 4 wk. Dogs were pretreated for 7 days before and on the morning of each test day with inhaled budesonide (2.69 mg/day) or a placebo (lactose). Airway eosinophil numbers were assessed by bronchoalveolar lavage. Inhaled budesonide significantly reduced the number of airway eosinophils before allergen inhalation from 3.6 +/- 2.38 x 10(4) (SE) cells/ml after inhaled lactose to 0.3 +/- 0.21 x 10(4) cells/ml after inhaled budesonide (P = 0.028). The decrease in eosinophil number was associated with a significant reduction in allergen-induced airway hyperresponsiveness (P = 0.005). These results support the hypothesis that the number of eosinophils in the airways before allergen inhalation is an important determinant in the development of allergen-induced airway hyperresponsiveness in dogs.

[Current aspects of fungal spores allergy]

In industrialized countries the prevalence of allergic inhalant diseases is some 15-20%. More than 10% of these individuals are sensitized to fungal allergens. Many fungal spores are less than 10 microns in size, which permits penetration into the smaller airways of the lung. Bronchial provocation tests have demonstrated that fungal spores and spore extracts can cause both an early and a late phase reaction in sensitive subjects. Over 80 genera of fungi have been associated with symptoms of respiratory tract allergy. Ascomycetes, basidiomycetes and zygomycetes are the major fungal groups that contain genera known to induce and elicit allergic reactions. These groups contribute most of the spores found in air. Although ascomycetes include the greatest number of any fungal group, only a few species, such as Aspergillus fumigatus, Alternaria alternata and Cladosporium herbarum, have been investigated in a scientific manner. In recent years spores of basidiomycetes have been tested for allergenicity and some species have been determined to be allergenic, such as Calvatia cyathiformis, Ganoderma applanatum, Pleurotus ostreatus, or Psilocybe cubensis. Compared to pollen-related allergies, diagnosis of fungal allergy is often difficult. Provocative challenge with specific fungal antigens can provide a definitive diagnosis. To date, only three controlled immunotherapy trials with standardized extracts of A. alternata and C. herbarum have shown clinical efficacy. In spite of these studies, immunotherapy with fungal antigens requires further investigations. Thus, the indication for immunotherapy with fungal extracts must be judged by an experienced allergist. Apart from pharmacological management, avoiding or minimizing exposure is the front-line measure.

Effect of allergen avoidance in infancy on allergic manifestations at age two years

BACKGROUND

One hundred twenty children, identified before birth as being at high risk for atopy, were prenatally assigned to prophylactic or control groups.

METHODS

The infants in the prophylactic group either received breast milk from mothers on an exclusion diet or an extensively hydrolyzed formula. Their bedrooms and living rooms were treated repeatedly with an acaricide, and they used polyvinyl-covered mattresses with vented head areas. The infants in the control group were fed conventionally, and no environmental control was recommended.

RESULTS

A significant advantage, first demonstrated at 1 year of age, persists for children in the prophylactic group. They have less of any allergy or eczema, but the reduced prevalence of asthma is no longer significant. Only three children in the prophylactic group had positive skin prick test results compared with 16 in the control group, suggesting a significant reduction in sensitization.

CONCLUSION

A dual approach to allergen avoidance, focusing on foods and aeroallergens, appears to be beneficial in selected high-risk infants. Avoidance of potent allergens in early life increases the threshold for sensitization in these high-risk infants. Whether sensitization has been avoided or merely deferred has yet to be proved.

[Prevention of exposure in respiratory allergies]

Sensitization to indoor allergens like house-dust mite and animal dander as well as outdoor allergens like grass and tree pollen play an important role in the development to atopic airway disease, i.e. atopic rhinitis and conjunctivitis and allergic asthma. Studies on emergency room patients in the US showed that the sensitization to cat dander and house-dust mite Dermatophagoides represented risk factors for acute attacks of asthma. However, irrespective of the inheritance of atopy, disease of specific organs and expression of symptoms remain highly variable and are likely to depend on a multiplicity of environmental factors, the most important of which is likely to be the level of exposure to the sensitizing allergen. There is increasing evidence that exposure to potential allergens early in life is important. Concentrations and timing of the exposure seem fundamental. The elimination of allergens in households of atopic individuals is crucial in a prophylaxis and therapy. There have been several publications on mite allergen elimination procedures; a lot of them are uncontrolled, and allergen reduction is not significant. This article tries to compare trials reporting of improvement of clinical symptoms and significant reduction of indoor allergens with those trials which did not achieve significant results.

A magnetic resonance imaging evaluation of histamine-mediated allergic response in the guinea pig nasopharynx

BACKGROUND

Magnetic resonance imaging (MRI) is a powerful technique for visualizing tissues with a high water content. In this study we used MRI to evaluate the effect of antigen and mediators of allergic responses on the nasopharyngeal airway of guinea pigs.

METHODS AND RESULTS

Longitudinal relaxation time-weighted transverse images of the nasopharyngeal airway revealed a clearly defined airway lumen and mucosa. Topical administration of ovalbumin (0.00006% to 0.06%) to the nasopharyngeal airway of sensitized guinea pigs caused a concentration-dependent reduction (34% +/- 1%, maximum) in airway luminal volume and a corresponding increase (28% +/- 3%, maximum) in the volume of the airway mucosa. These effects were duplicated by histamine (10(-5) to 10(-3) mol/L), but not by methacholine (10(-3) mol/L). The antigen-induced changes in airway and mucosal volumes were dose-dependently inhibited by the H1-antagonist loratadine (0.3 to 3 mg/kg, administered orally). On the other hand, topical administration of a decongestant drug, oxymetazoline (250 micrograms per guinea pig), had no effect on the response to antigen.

CONCLUSIONS

These results indicate that MRI is a useful technique to measure allergic responses in the airways and identify that histamine is an important mediator of the obstruction that occurs in the nasopharyngeal airway of guinea pigs after antigen challenge.

[Habitual vomiting due to dust mite allergy. A case report]

It has been demonstrated that: a) part of the inhalant allergenic particles we normally breath, adhere to the oropharyngeal mucosa, and eventually progress to the gastrointestinal tract; b) digestive tract mucosa is able to produce specific IgE against aeroallergens even before than respiratory tract mucosa. The case is described of a 5-year-old girl who presented a daily vomiting since she was 6 months. All clinical instrumental and laboratory findings had been unable to reach a definite diagnosis. SPT (inhalants and foods): Dermatoph. pteronyssinus: + (confirmed by RAST). The patient had an immediate, complete recover just following the clinician's instruction for HDM domestic prevention. Symptoms appeared again in response to a NPT performed with Dermatophagoides extract. The positivity of the exclusion-re-exposure test confirmed the diagnosis of HDM-induced gastrointestinal allergic syndrome, so far not described in literature (to my knowledge). Immunological considerations: since it is known that patients allergic to HDM do not usually present a specific IgE-mediated gastrointestinal allergic syndrome, it is suspectable that an immunological tolerance can be instaured toward inhalant allergens as it normally happens toward food allergens. In atopic individuals there is a high expression of ICAM-1, VCAM-1 and other adhesion molecules on the surface of HEV at BALT level. Adhesion molecules expression and immunocompetent cells activation are modulated by several mechanisms among which the cytokine network plays a major role. The author speculates that sensitized lymphocytes may migrate from intestinal to bronchial mucosa, via lymphocytic immunoallergic competence. In the described clinical case this mechanism did not work.

[Sensitization to house dust mites: importance and possibilities of allergen elimination]

House-dust mite allergy (Dermatophagoides pteronissinus and Dermatophagoides farinae) is an important causative factor for allergic asthma or rhinitis in children. There is a clear relationship between the degree of allergen exposure and the subsequent development of asthma or the risk of sensitisation. It is therefore useful to know how intensive a patient is exposed to house-dust allergen. This can be managed either by counting all mites in the dust, by measuring of the content of Der p I and Der f I (major antigens of the two mites) per gram dust or using the Acarex test. These methods are also suitable for the control of sanitation measurements, e.g. avoidance of all dust sources in the bedroom and living-room, use of suitable materials for bedding, application of acaricide products and covering mattresses with polyurethane-coated materials.

SO2-induced enhancement of inhalative allergic sensitization: inhibition by anti-inflammatory treatment

Epidemiological studies have shown a relationship between air pollution and allergic airway disease. In a previous study we have found that exposure to SO2 enhances allergic sensitization to inhaled ovalbumin (OA) in the guinea pig. We have now investigated the influence of pre-treatment with anti-inflammatory drugs on SO2-induced enhancement of allergic sensitization in this model. Four groups of 6 guinea pigs each were exposed to 5 ppm SO2 on 5 consecutive days over 8 h per day with intermittent inhalation of OA, while the air-control group was exposed to clean air and OA. During the period of SO2 exposure and sensitization three experimental groups were treated with indomethacin (group I), methylprednisolone (group M) and nebulized nedocromil sodium (group N), while the control group remained untreated. Guinea pigs were investigated for sensitization to OA by specific bronchial provocation tests using body plethysmographic measurement of compressed air (CA) and by measurement of specific antibody response in serum. While in the SO2-exposed control group 5 of 6 animals reacted to specific bronchial provocation testing (CA median 0.15 ml, range 0-0.175 ml), only 1 animal was sensitized in group M (CA 0 ml, 0-0.125, p < 0.05), whereas no bronchial reactions were seen in groups I and N (CA 0 ml, 0-0.05, p < 0.025). Specific IgG antibody titres increased in the control group (median 43 EU-->85 EU), but not in the treatment groups (medians group I 35 EU-->35 EU, group M 30-->35 EU, group N 64-->50 EU).(ABSTRACT TRUNCATED AT 250 WORDS)

Suppression of pulmonary hypersensitivity granulomas in mice by superoxide dismutase

Pulmonary hypersensitivity granulomas were induced in immunized mice by the intratracheal injection of antigen-coupled agarose beads. Foreign body lung granulomas were induced in mice by the intratracheal injection of dextran beads. Both lesions developed within 1 day, reached peak intensity within 3 days, and gradually declined in size thereafter. Hypersensitivity granulomas were much larger than foreign body lesions. The lung extracts prepared from mice with hypersensitivity lung granulomas, but not foreign body lesions, contained high levels of superoxide dismutase (SOD) and thiobarbiturate-reactive substances including lipid peroxides. SOD activity and levels of thiobarbiturate-reactive substances in the extracts correlated with sizes of hypersensitive lesions. Hypersensitivity granulomas, but not foreign body lesions, were inhibited by the administration of recombinant human SOD (rh-SOD). Thiobarbiturate-reactive substances were decreased in the lung extracts of mice bearing hypersensitivity granulomas injected with rh-SOD. These results suggest that reactive oxygen intermediates such as superoxide anion may play an important role in the development of hypersensitivity granulomas and that rh-SOD is capable of inhibiting the lesions by its antioxidant action.

Efficacy of an air-cleaning device equipped with a high efficiency particulate air filter in house dust mite respiratory allergy

The efficacy of an air-cleaning device equipped with a high efficiency particulate air (HEPA) filter (without further avoidance measures) was studied in patients allergic to house dust mite. The effects of the air-cleaner on indoor Dermatophagoides sp. levels, symptom score and bronchial hyperresponsiveness in nine mite-allergic patients were assessed using a cross-over controlled study. No significant effect was demonstrated on indoor Dermatophagoides sp. levels when comparing the period of air-cleaner activity (2 months) with the control period (2 months). The Dermatophagoides sp. levels in the houses studied were lower than the risk level for asthmatic attacks, making it difficult to assess any effect on asthma; however, neither bronchial hyperresponsiveness nor rhinitis symptom score were changed by air-cleaner activity. During the trial period, however the mean level of Dermatophagoides sp. allergen in the houses changed spontaneously from 4.4 micrograms/g (mean level in the first 2 trial months) to 1.75 micrograms/g of dust (second 2 months) (P less than 0.05). Owing to this change, the mean rhinitis symptom score also decreased (P less than 0.05), even if no significant correlation was demonstrated (r = 0.4 P = 0.089). HEPA filter air-cleaners appear insufficient as substitutes for standard avoidance measures in mite allergic patients.

BI-L-239, a 5-lipoxygenase inhibitor, blocks inhaled antigen-induced airway hyperresponsiveness in conscious guinea pigs

Male Hartley guinea pigs were actively sensitized to ovalbumin (OA). Respiratory system resistance (Rrs) was measured by forced oscillations superimposed on tidal breathing. Airway responsiveness (inhaled methacholine PC100) was determined three days prior and three days after (day 10) three alternate day inhalations of OA. Airway cell composition was assessed on day 10 by lung lavage. Three groups (n = 5-6) were studied: A) vehicle challenged, B) OA challenged/placebo treated, C) OA challenged/BI-L-239 (2,6-dimethyl-4-[2-(4-fluorophenyl)ethenyl]phenol) treated (10 x 0.75 mg/actuation, 10 minutes prior to each OA challenge). Animals were treated with pyrilamine and indomethacin (10 mg/kg i.p.) 30 minutes prior to each OA challenge. OA induced acute increases in Rrs of 143 +/- 29%, 238 +/- 73% and 102 +/- 43% in placebo and 86 +/- 34%, 45 +/- 35% (p, 0.05 vs. placebo) and 102 +/- 31% in BI-L-239 treated. OA induced a significant (p less than 0.05) increase in airway leukocytes in placebo (487 +/- 36 to 1615 +/- 421 x 10(3)/ml) but not BI-L-239 treated (to 881 +/- 155 x 10(3)/ml) and decrease in methacholine PC100 in placebo (1.487 +/- 0.49 to 0.39 +/- 0.18 mg/ml) but not BI-L-239 treated (0.99 +/- 34 to 1.04 +/- 0.39 mg/ml). We conclude that BI-L-239 attenuates the airway constriction, inflammation and hyperresponsiveness induced by repeated antigen inhalations in conscious guinea pigs.

[The main hygienic aspects of biotechnological processes]

It was shown that the present technologies and implementation at the majority of biotechnological plants do not completely meet the hygienic requirements. Under such conditions, there is a complex of unfavourable factors which can have a negative effect on the production areas and environment and consequently on the workers and nearby population. The biological and, at some plants, chemical factors are the leading in the complex. The main aspects of the studies aimed at increasing the safety of biotechnological production, improving the labor conditions and decreasing the disease incidence in the personnel are described in general.