Although viral upper respiratory infections (URIs) provoke wheezing in many asthma patients, the effect of these illnesses on the airway response to inhaled antigen is not established. The following study evaluated the effect of an experimental rhinovirus (RV) illness on airway reactivity and response to antigen in 10 adult ragweed allergic rhinitis patients. Preinfection studies included measurements of airway reactivity to histamine and ragweed antigen. Furthermore, the patients were also evaluated for late asthmatic reactions (LARs) to antigen (a 15% decrease in forced expiratory volume of the first second approximately 6 h after antigen challenge). 1 mo after baseline studies, the patients were intranasally inoculated with live RV16. All 10 patients were infected as evidenced by rhinovirus recovery in nasal washings and respiratory symptoms. Baseline FEV1 values were stable throughout the study. During the acute RV illness, there was a significant increase in airway reactivity to both histamine and ragweed antigen (P = 0.019 and 0.014, respectively). Before RV inoculation, only 1 of the 10 subjects had an LAR after antigen challenge. However, during the acute RV illness, 8 of 10 patients had an LAR (P less than 0.0085 compared with baseline); the development of LARs was independent of changes in airway reactivity and the intensity of the immediate response to antigen. Therefore, we found that not only does a RV respiratory tract illness enhance airway reactivity, but it also predisposes the allergic patient to develop LARs, which may be an important factor in virus-induced bronchial hyperresponsiveness.

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Rhinovirus upper respiratory infection increases airway hyperreactivity and late asthmatic reactions.

Damp indoor spaces and health , Damp indoor spaces and health , کتابخانه دیجیتال جندی شاپور اهواز

Damp Indoor Spaces and Health

The relation between the health of workers and the environment in swine confinement buildings was investigated in a study of 57 workers on 30 swine farms in southern Sweden and 55 matched controls. Swine workers reported significantly higher frequencies of respiratory symptoms, more frequent colds and absence due to chest illness, and a history of pneumonia. The increased frequency of symptoms of respiratory disease was related to the number of years and percent of the day spent working with swine. Symptoms were also associated with respirable dust, total dust, endotoxin in total dust, and number of microbes in the air of the work environment. In a multiple regression analysis of the relation between 16 different environmental parameters to work period shifts of five pulmonary function parameters, endotoxin was found to be significantly related to the FEV1 in a dose dependent way.

https://oem.bmj.com/content/oemed/46/1/31.full.pdf

Environmental and health studies of farm workers in Swedish swine confinement buildings.

SUMMARY A wide variety of microbial species are used in food and feed production. Some have a long history of apparent safe use, while others are less well understood and their use may represent a risk for consumers. Experience has shown that there is a need for a tool for setting priorities within the risk assessment of those microorganisms used in food/feed production referred to EFSA and consequently the subject of a formal assessment of safety. To meet this need a system was proposed for a pre-market safety assessment of selected groups of microorganisms leading to a “Qualified Presumption of Safety (QPS)”. In essence this proposed that a safety assessment of a defined taxonomic group (e.g. genus or group of related species) could be made based on four pillars (establishing identity, body of knowledge, possible pathogenicity and end use). If the taxonomic group did not raise safety concerns or, if safety concerns existed, but could be defined and excluded (the qualification) the grouping could be granted QPS status. Thereafter, any strain of microorganism the identity of which could be unambiguously established and assigned to a QPS group would be freed from the need for further safety assessment other than satisfying any qualifications specified. Microorganisms not considered suitable for QPS would remain subject to a full safety assessment. EFSA asked its Scientific Committee to consider whether this system could be used to harmonise approaches to the safety assessment of microorganisms across the various EFSA scientific panels. If so, the Committee was requested to develop a strategy for the introduction of an assessment system based on the QPS concept.

Introduction of a Qualified Presumption of Safety (QPS) approach for assessment of selected microorganisms referred to EFSA 1 Opinion of the Scientific Committee

Bioaerosols and occupational lung disease

As part of a project to evaluate health hazards for workers in swine confinement buildings, the air in 21 different buildings was sampled with 37 mm cassette filters with and without cyclone preselectors and with cascade impactors. Filter results yielded a mean total aerosol of 6.3 mg/m3, a mean respirable aerosol of 0.5 mg/m3; the geometric mean diameter was 2.9 microns. Cascade impactor measurements revealed a mean total aerosol of 7.6 mg/ m3, a respirable aerosol of 2.5 mg/ m3 and a mass median diameter of 9.6 microns. The two major constituents in these aerosols were grain particles and dried fecal matter. The grain particles were larger than fecal particles and proportionately more abundant in finishing buildings where 50 kg-100 kg animals are housed. Therefore the respirable fraction was less in finishing buildings than in farrowing and nursery buildings. Culturing of settled dusts yielded six different mold species, with the highest counts for Verticillium sp. (5 × 102 cfu/mg dry dust) grown at 37°...

Characterization of dusts collected from swine confinement buildings

Viral respiratory infections provoke asthma in many patients. In the following study we examined the effect of an in vitro incubation of influenza A on leukocyte histamine release. After incubation with a live influenza A (H3N2) virus, calcium ionophore A23187 (0.5, 1.0, and 1.5 microgram/ml)-induced leukocyte histamine release (HR) was enhanced (p less than 0.05). This effect was also found with heat- or ether-inactivated virus. Similarly, influenza A-exposed leukocytes had augmented leukocyte HR during subsequent incubation with ragweed AgE. Incubation of the leukocyte suspension with interferon (800 IU/ml) for 24 hr was also associated with enhanced HR to ragweed AgE. In contrast, interferon did not alter the calcium ionophore A23187 HR. Therefore, although interferon may mediate the enhanced leukocyte HR when ragweed AgE is the inciting stimulus, it does not change HR to the calcium ionophore.

Effect of influenza A virus on leukocyte histamine release.

Detection of proteinases in electrophoretograms of complex mixtures.

A patient employed in a plant where blue cheese was manufactured developed hypersensitivity pneumonitis to Pencillium roqueforti. Symptoms of cough, dyspnea, and malaise, and findings of bibasilar crackles, reduced lung volumes, hypoxemia, and bilateral infiltrates on chest roentgenogram, resolved after she left the workplace. Bronchoalveolar lavage revealed a high percentage of lymphocytes. Antibody to P. roqueforti was demonstrated in serum and lavage fluid. To our knowledge this case represents a new occurrence of hypersensitivity lung disease in the cheese manufacturing industry in the United States.

Cheese worker's hypersensitivity pneumonitis.

Sera from 12 patients with farmer's lung disease (FLD) drawn during an acute episode and dis­ playing precipitins to Micropolyspora faeni were analyzed by crossed immunoelectrophoresis with an intermediate gel combined with a rabbit reference precipitate system, Forty-six precipitin arcs were identified in the reference precipitate system, and FLD sera reacted with 36 of these antigens. The FLD sera displayed significantly more precipitates and higher precipitin scores when com­ pared with sera from 16 precipitin-positive subjects who did not have FLD. However, there was overlap between the 2 groups, and neither measurement distinguished the 2 persons who became ill after challenge from one person who did not. Three disease specific antigens were identified that may have special relevance for pathogenesis of disease. Ten exposure-relevant antigens were also identified_ We propose that these antigens be important components of a standardized M_ faeni antigen preparation_

Mary W. Treuhaft

Papers

Characterization of dusts collected from swine confinement buildings

Effect of influenza A virus on leukocyte histamine release.

Detection of proteinases in electrophoretograms of complex mixtures.

Cheese worker's hypersensitivity pneumonitis.

Characterization of precipitin response to Micropolyspora faeni in farmer's lung disease by quantitative immunoelectrophoresis.