Exposure and respiratory health in farming in temperate zones--a review of the literature. (41/308)

To review studies in farming populations from temperate zones focusing on: (1) exposure to dust, bacteria, moulds, endotoxin, and ammonia, (2) sensitisation to common airborne allergens, (3) prevalence, incidence and risk factors of chronic bronchitis, asthma and bronchial hyperresponsiveness, and (4) measurements of lung function. Working in animal housings can be associated with exposure to organic dust, bacteria, moulds, endotoxin, and ammonia in concentrations that can induce cellular and immunological responses and result in respiratory diseases. Working in poultry housing might be associated with higher exposures to dust, bacteria, and ammonia than in swine and cow housings, and endotoxin exposure seems to be higher in North America than in Europe. Working exposure might influence the domestic area on farms, and there might be a protective effect of being raised on a farm regarding sensitisation and allergic diseases. Sensitisation to mites seems to be the most prevalent of the common inhalant allergens. Chronic bronchitis is frequent and data suggests that it is work related in farmers. Findings concerning asthma are less uniform, and data regarding bronchial hyperresponsiveness are too sparse and inconsistent to evaluate the effect on farming. Several risk factors have been described, and age is shared for all three clinical manifestations, while male gender, atopy, smoking, pig farming, and animal production are common risk factors for chronic bronchitis and asthma. FEV(1), and FEV(1)/FVC seems to be reduced in farmers, and longitudinal studies indicate an increased annual loss in FEV(1) in farmers, especially in pig farmers. The increased annual decline has been associated with lung function, bronchial hyperresponsiveness, smoking, automatic dry feeding systems, and endotoxin. Despite studies with methodological weaknesses, heterogenity in sampling times, measurement techniques, equipment, and diagnostic criteria, the review has revealed that the exposure to organic dust in farming can be substantial and might lead to respiratory diseases and increased annual loss in lung function. Working exposure seems to influence the domestic area in farms, and being raised on a farm might have a protective effect regarding sensitisation and allergic diseases.  (+info)

Primary endobronchial actinomycosis associated with broncholithiasis. (42/308)

Primary endobronchial actinomycosis is an extremely rare disease that presents with endobronchial mass. We report 2 cases of primary endobronchial actinomycosis associated with broncholithiasis. There was no foreign body material, suggesting that these broncholiths were formed endogenously. Even though it is very rare, endobronchial actinomycosis should be included in the differential diagnosis of calcified endobronchial mass, especially when there is no clinical or radiological evidence of a granulomatous infection, such as tuberculosis, and the yellowish materials obstructing the bronchi are seen during bronchoscopy.  (+info)

Anaesthesia and tracheobronchial stenting for central airway obstruction in adults. (43/308)

In the last decade, stents suitable for the management of tracheobronchial stenoses and obstruction have evolved from bulky prostheses requiring tracheal resection to small devices that are self-expanding and can be inserted using fibreoptic techniques. The experience base for this review is more than 100 patients between 1989 and 2001 who have been anaesthetized for stent insertion. Early cases required rigid bronchoscopy for the routine of insertion. Anaesthetic techniques have evolved from those that were designed and developed for laser surgery in the central airways. The advent of modern devices now extends the variety of anaesthetic management techniques that can be used. But the original one, based on the requirement for use of a rigid bronchoscope, is best for dealing with complications and extracting problem stents. The most frequent complication of the processes of stent insertion has been respiratory failure because of carbon dioxide retention, consequent on obstruction with secretions in the area of the carina. The nature of central airway problems suggests that anaesthesia induction, management and teaching should not be founded on the conventional model-base of upper airway obstruction.  (+info)

Bronchodilation in infants with malacia or recurrent wheeze. (44/308)

BACKGROUND: Controversy remains regarding the effectiveness of bronchodilators in wheezy infants. AIMS: To assess the effect of inhaled beta(2) agonists on lung function in infants with malacia or recurrent wheeze, and to determine whether a negative effect of beta(2) agonists on forced expiratory flow (V'(maxFRC)) is more pronounced in infants with airway malacia, compared to infants with wheeze. METHODS: We retrospectively analysed lung function data of 27 infants: eight with malacia, 19 with recurrent wheeze. Mean (SD) age was 51 (18) weeks. Mean V'(maxFRC) (in Z score) was assessed before and after inhalation of beta(2) agonists. RESULTS: Baseline V'(maxFRC) was below reference values for both groups. Following inhalation of beta(2) agonists the mean (95% CI) change in mean V'(maxFRC) in Z scores was -0.10 (-0.26 to 0.05) and -0.33 (-0.55 to -0.11) for the malacia and wheeze group, respectively. CONCLUSIONS: In infants with wheeze, inhaled beta(2) agonists caused a significant reduction in mean V'(maxFRC). Infants with malacia were not more likely to worsen after beta(2) agonists than were infants with recurrent wheeze.  (+info)

Occupational and nonoccupational factors associated with high grade bronchial pre-invasive lesions. (45/308)

Besides tobacco exposure, factors associated with the development of pre-invasive bronchial lesions are not known. Autofluorescence bronchoscopy was used to assess the prevalence of severe dysplasia and carcinoma in situ (SD/CIS) of the proximal bronchial tree in relation to occupational or nonoccupational carcinogen exposure. Among the 241 individuals in this study, the overall prevalence of at least one SD/CIS was 9% (21 subjects). Multivariable analysis revealed significant and independent associations between presence of SD/CIS and: 1) active smoking, relative to former smokers; 2) presence of synchronous invasive lung cancer; 3) duration of asbestos exposure and; 4) exposure to other occupational carcinogens. The independent associations of synchronous lung cancer with severe dysplasia and carcinoma, after adjusting for both occupational and nonoccupational carcinogen exposures, suggest other mechanisms than a field cancerisation may be involved in the carcinogenesis of these pre-invasive lesions. Moreover, active smokers, patients with recently resected invasive lung cancer and workers occupationally exposed to bronchial carcinogens may represent a population of choice for early cancer endoscopic detection programmes in view of their high severe dysplasia and carcinoma prevalence.  (+info)

Application of high-density DNA microarray to study smoke- and hydrogen peroxide-induced injury and repair in human bronchial epithelial cells. (46/308)

Recent advances in high-density DNA microarray technique allow the possibility to analyze thousands of genes simultaneously for their differential gene expression patterns in various biologic processes. Through clustering analysis and pattern recognition, the significance of these differentially expressed genes can be recognized and correlated with the biologic events that may take place inside the cell and tissue. High-density DNA microarray nylon membranes were used to explore gene expression and regulation associated with smoke- and hydrogen peroxide-induced injury and repair in differentiated human bronchial epithelial cells in vitro. At least three phases of change in gene expression could be recognized. The first phase seems to be an immediate event in response to oxidant injury. This phase includes the induction of bcl-2 and mdm2 genes that are involved in the regulation of apoptosis, and the mitogen-activated protein kinase phosphatase 1 that functions as a regulator for various mitogen-activated protein kinase activities. The second phase, usually 5 h later, includes the induction of various stress proteins and ubiquitin, which are important in providing the chaperone mechanism and the turnover of damaged macromolecules. The third phase, which is 5 to 10 h later, includes the induction of genes that seem to be involved in reducing oxidative stress by metabolizing the cellular level of reactive oxygen species. In this phase, enzymes associated with tissue and cell remodeling are also elevated. These results demonstrated a complex gene expression array by bronchial epithelial cells in response to a single insult of oxidants that are relevant to environmental pollutants.  (+info)

TGF-beta1 causes airway fibrosis and increased collagen I and III mRNA in mice. (47/308)

BACKGROUND: Subepithelial collagen and extracellular matrix protein deposition are important pathophysiological components of airway remodelling in chronic asthma. Animal models based on the local reaction to antigens show structural alterations in the airway submucosal region and provide important information regarding disease pathophysiology. We describe a murine model of peribronchial fibrosis using intratracheally instilled transforming growth factor (TGF)-beta(1) in BALB/C mice that facilitates a mechanistic approach to understanding the cellular and molecular pathways leading to airway fibrosis. METHODS: BALB/C mice were intratracheally instilled with either TGF-beta(1) or buffered saline. Airway fibrosis was assessed by light microscopy, hydroxyproline content, and polymerase chain reaction (PCR) for collagen I and III on microdissected airway samples. The lysyl oxidase inhibitor beta-aminoproprionitrile (BAPN) was administered to TGF-beta(1) treated mice to block airway collagen deposition. Airway hyperresponsiveness was also measured after treatment with TGF-beta(1). RESULTS: During the 7 days after administration of TGF-beta(1) the mice developed increased subepithelial collagen which could be blocked by BAPN. Increased mRNAs for collagen types I and III were seen in microdissected airways 1 week after TGF-beta(1), and significantly increased total collagen was found in the airways 4 weeks after TGF-beta(1). A detectable increase in airway hyperreactivity occurred. CONCLUSIONS: This new model should facilitate detailed study of airway remodelling that occurs in the absence of detectable cellular inflammation, and allow examination of the functional consequences of a major structural alteration in the conducting airways uncomplicated by inflammatory cell influx.  (+info)

Seven patients with plasma cell granuloma (inflammatory pseudotumor) of the lung, including two with intrabronchial growth: an immunohistochemical and electron microscopic study. (48/308)

Seven patients (mean age, 50.7 +/- 20.4 years; range 21-77) with plasma cell granuloma (PCG) of the lung are reported. Cough and sputum were the most common presenting symptoms, followed by fever. Elevated erythrocyte sedimentation rate and serum C-reactive protein levels were found in all patients tested. Radiologically, five cases presented as solitary, well-circumscribed masses and two as ill-defined, pneumonia-like densities. One showed focal calcification. No predilection of occurrence was observed in either lobe of the lung. Histologically, the lesions consisted of a proliferation of mature plasma cells and reticulo-endothelial cells supported by a stroma of granulation tissue, with varying degrees of myxoid change or collagenization. Angioinvasion within the lesion was observed in 4 of the 7 cases. Immunohistochemical staining revealed the IgG-predominant polyclonal nature of the plasma cells, indicating a reactive inflammatory process rather than a neoplastic one. Electron microscopy confirmed the benign nature of the plasma cells with fibroblast and myofibroblast proliferation admixed with that of other inflammatory cells.  (+info)