Changes In Bronchial Mucosa Research Articles

The impact of the weakly-fibrogenic bauxite dust on lungs in mine workers

Introduction. New cases of pneumoconiosis are detected annually at the bauxite mining enterprises of the Sverdlovsk Region. Differential diagnosis of bauxite pneumoconiosis with other interstitial lung diseases using only lung radiography can be difficult. The aim of the work was to clarify the nature of changes in the lungs of workers exposed to weakly fibrogenic dust of bauxite, and the relationship of changes in the lungs with working conditions in cases of difficulty in making the final diagnosis of pneumoconiosis. Material and methods. Underground miners of a working face and underground drifters with a work experience of at least ten years in conditions of exposure to bauxite dust were examined. All patients underwent a plain chest x-ray and high-resolution computed tomography (HRCT), bodyplethysmography, bronchoscopic examination with trans-bronchial biopsy, and subsequent histological examination of the biopsy. To determine the elemental composition of micro- and nanoparticles in biological tissue samples, scanning electron microscopy with X-ray spectral microanalysis was used. Results. During the histopathological examination of lung tissue biopsy materials by a bright-field method and polarized filter and using electron microscopy, the composition of dust in the lung tissue complied with the composition of industrial aerosol. It is formed during bauxite mining (aluminum, iron, and quartz compounds). High-resolution computed tomography (HRCT) and bronchoscopy can detect signs of exposure to industrial aerosol of complex composition represented by early interstitial parenchymal fibrosis and changes in bronchial mucosa. This is typical for individuals at risk of occupational respiratory diseases development without radiological features specific to pneumoconiosis. Before X-ray pattern formation, typical for pneumoconiosis, bronchitis syndrome and atrophic changes in the bronchial mucosa are developed. This happens in workers exposed to weakly-fibrogenic dust of a complex composition formed during the mining of bauxite. The changes are permanently observed long after the exposure to the dust factor has ceased.

Carcinogenic and genotoxic risks of combined exposure to dust and radiation in oxidative stress environment

Rats subjected to coal dust combined with radiation dose of 6 Gy in long-term period demonstrated cytogenetic disorders and changes in bronchial mucosa, arterial and arterioli walls in lung stroma, destructive changes in liver parenchyma with colliquation necrosis foci in liver lobules, on oxidative stress background. Findings are that combined experimental exposure to dust and radiation on oxidative stress background increases carcinogenic and genotoxic risks in animals.

Changes in bronchial mucosa in smokers with chronic obstructive pulmonary disease

The aim of the study was to describe tissue, cellular and molecular particularities of the bronchial mucosa in smokers with chronic obstructive pulmonary disease (COPD). Methods. Morphological investigation of bronchial wall biopsy in smokers with and without COPD was made. Results. Bronchial wall structural disorders were seen in smokers without clinical manifestations of the disease which were considered as compensatory changes. Morphological features of hemodynamic abnormalities, perivascular fibrosis of the lamina propria, squamous cell metaplasia, atrophy of the bronchial epithelium associated with endothelial dysfunction and dysregeneration of the epithelial cells were found in smokers with clinically significant COPD. Conclusion. Morphological changes in bronchial wall are thought to be related to COPD severity.

Relation between vascular patterns visualized by narrow band imaging (NBI) videobronchoscopy and histological type of lung cancer

Narrow Band Imaging (NBI) videobronchoscopy is a new technique for visualization of microvascular changes in bronchial mucosa. The primary aim of this study was to evaluate relation between vascular patterns visualized by NBI and histology of lung cancer. We prospectively evaluated 65 patients with suspected lung cancer scheduled for bronchoscopy. NBI followed conventional WL videobronchoscopy. After identification of endoscopically visible tumor, NBI was used to determine predominant type of pathological vascular pattern (dotted, tortuous, abrupt-ending blood vessels-Shibuya descriptors). All the lesions were biopsied and histologically confirmed. There were 81.5 % male and 18.5 % female patients evaluated in the study. Lung cancer was confirmed in all patients; 63.1 % were diagnosed with squamous cell lung cancer (SCC), 24.6 % had adenocarcinoma, 9.2 % had small-cell (SCLC) and 3.1 % large-cell lung cancer (LC). Dotted blood vessels were significantly (p < 0.000) associated with adenocarcinoma, identified in 68.4 % adenocarcinoma and 31.6 % SCC. Tortuous blood vessels were identified in 72 % SCC, 8 % adenocarcinoma, 12 % SCLC and 8 % of LC. Tortuous blood vessels were significantly (p < 0.000) associated with SCC. Abrupt-ending vessels were identified in 81 % SCC, 14.3 % SCLC and 4.8 % adenocarcinoma and were significantly associated (p < 0.000) with SCC. Dotted visual pattern of blood vessels identified during NBI videobronchoscopy is highly suggesting adenocarcinoma histology of lung cancer. Tortuous and abrupt-ending blood vessels visualized under NBI videobronchoscopy significantly suggest squamous cell histology of lung cancer. Large-scale studies should be designed in order to determine true relation between visual appearance and histology in lung cancer.

AB 10. Relation between histological types of lung cancer and vascular patterns visualized by narrow band imaging (NBI) videobronchoscopy

Background Narrow Band Imaging (NBI) videobronchoscopy is a new technique for visualization of microvascular changes in bronchial mucosa. The primary aim of this study was to evaluate relation between vascular patterns visualized by NBI and histology of lung cancer.

Autofluorescence bronchoscopy in volunteer asymptomatic smokers

We assess the sensitivity of autofluorescence bronchoscopy (AFB) compared to that of white light bronchoscopy (WLB) for identification of pre-invasive neoplastic changes of bronchial mucosa in asymptomatic heavy smokers. WLB was performed using a standard flexible fibre-optic bronchoscope, and AFB carried out using the Xillix LIFE Lung((R)) system. Positive AFB images were indicated in the bronchial tree from 51 of the 93 subjects in the study. Biopsies showed epithelial abnormalities in 27 (15 metaplasia, 12 inflammatory changes) of these. WLB showed abnormality in 1 subject but with no pathological changes revealed by cyto-histology. Therefore, the sensitivity of AFB to metaplasia was 75% compared to zero for WLB. AFB yields positive predictive values for metaplastic and overall mucosal changes of 29.4% and 52.9%, respectively. In summary, over 16% of asymptomatic smokers had metaplastic changes in their bronchial mucosa, and AFB proved more sensitive in revealing early changes than WLB.

Is Autofluorescence Bronchoscopy Needed to Diagnose Early Bronchogenic Carcinoma?

Is Autofluorescence Bronchoscopy Needed to Diagnose Early Bronchogenic Carcinoma?

AUTOFLUORESCENCE BRONCHOSCOPY IN THE DIAGNOSIS OF PRENEOPLASTIC CHANGES AND BRONCHIAL CARCINOMA

Background. Fluorescence bronchoscopy is more sensitive than white light bronchoscopy in the diagnosis of preneoplastic changes of bronchial mucosa, carcinoma in situ and invasive bronchial cancer. Methods. Thirty-one patients, 22 male, 9 female, age 59 ± 11 years were examined with autofluorescence system Storz 11004BI and D-light/AF with camera SL PDD and Olympus 1T30 or 1T40. Local anaesthesia was applied. Bronchial biopsy was performed 3–5 times on macroscopically suspicious and apparently normal sites of bronchial mucosa. Each biopsy site was classified by white light (WLB), autofluorescence bronchoscopy (AFB) and histologically as normal epithelium, moderate dysplasia, severe dysplasia, and carcinoma in situ or invasive carcinoma. The results of WLB and AFB were compared with histological diagnosis. Results. We confirmed invasive carcinoma in 16, carcinoma in situ in 1 patient, pleural mesothelioma in 1 and benign diseases in 13 patients. Findings were classified as squamous cell (n = 9), small cell (n = 4), adenocarcinoma (n = 3) and unclassifiable (n = 1) carcinoma. Biopsy was performed on 52 sites. Invasive carcinoma was histologically confirmed on 19 biopsy sites. WLB showed invasive carcinoma in 17 cases (89%) and AFB in 18 cases (95%). In the patient with carcinoma in situ WLB found mild dysplastic changes while AFB was positive. WLB sensitivity was 0.85 and AFB 0.95, while specificity of WLB was 0.91 and of AFB was 0.44. Relative sensitivity of WLB + AFB was 1.08 comparing with WLB alone. We observed false positive results because of former biopsies, bleeding, inflammation or scarring in patients with mild dysplasia and normal mucosa with WLB in 1 (3%) and with AFB in 5 (16%) cases. Conclusions. Autofluorescence was more sensitive than white light bronchoscopy in the diagnosis of invasive bronchial carcinoma, carcinoma in situ and dysplasia. False positive results must be considered.

Histological Examination of Bronchial Mucosa after Photodynamic Therapy Showing no Selectivity of Effect between Tumour and Normal Mucosa

.After the treatment for early stage bronchogenic carcinoma including carcinoma in situ with photodynamic therapy (PDT), the degree of bronchial mucosal damage was studied histologically. The influence of treatment modality on bronchial mucosa was also examined. Few studies of histological changes of bronchial mucosa caused by PDT have been done.The histological specimens of bronchial mucosa in patients who received PDT and had a complete response were reviewed retrospectively. Twenty-three patients with 24 carcinomas including six carcinomas in situ had been treated with PDT using argon dye laser, excimer dye laser with or without additional radiotherapy. The degree of epithelial and subepithelial changes was classified as normal, hyperplasia, metaplasia and as mild, moderate and marked fibrosis, respectively.Subepithelial fibrosis was seen after PDT in almost all cases even when the tumour was entirely superficial to this layer. As a whole, epithelial change was found to be hyperplastic in three and metaplastic in 13 cases. Subepithelial fibrosis were found to be mild in four, moderate in 13, and marked in four cases. No differences were seen between the effects with the excimer and argon dye lasers.As used at present, PDT in the bronchi has no selectivity between normal and tumour tissue but may have advantages over other techniques due to the lack of cumulative toxicity and the excellent healing.

Pathological changes according to the severity of asthma.

There have been many studies concerning pathological changes in bronchial mucosa from asthmatics; however, few studies has been carried out to evaluate pathological changes according to the severity of asthma. This study was designed to evaluate the cellular components in bronchoalveolar lavage fluid (BALF) and histological abnormalities in asthmatics according to the severity of asthma. Bronchoalveolar lavages, bronchoscopic biopsies and ultrastructural examinations were performed in 13 asthmatics and 11 (BAL) or four (biopsies) non-asthmatic controls. The proportions of epithelial cells and correlations with PC20Meth which reflects bronchial hyperresponsiveness. Light microscopic examination revealed loss of epithelium, inflammatory cell infiltrations and thickening of the basement membrane which also showed significant correlation with PC20Meth. Hypertrophy of airway smooth muscles and hyperplasia of mucous glands were prominent in asthmatics but there was no difference according to the severity of asthma. Ultrastructural examination revealed that basement membrane thickening on light microscopic examination is due to the increased subepithelial collagen deposition with normal thickness of basal lamina. These data suggest that loss of epithelial cells, infiltration of inflammatory cells, especially eosinophils, and increased deposition of subepithelial collagen play major roles in determining the severity of asthma and non-specific bronchial hyperresponsiveness.

Powdered Diatrizoic Acid for Radiography of the Respiratory Tract

Powdered diatrizoic acid as a contrast medium administered by inhalation and insufflation for visualization of the airways was tested in vitro and in 21 dogs. Good radiopacity of the contrast medium and its antibacterial activity was found in vitro. In the majority of animal experiments visualization of the bronchial tree down to segmental and partially to subsegmental bronchi with only minimal agglomeration of contrast medium and with good or very good demonstration of anatomic details was achieved. In the majority of dogs contrast medium was eliminated from the lungs within 18 hours. Arterial blood gases tested on 5 dogs showed only unimportant changes after contrast medium administration. No adverse reactions were observed. Histologic and ultrastructural examinations after contrast studies showed phagocytic reaction to diatrizoic acid, transient impairment of production of surfactant, reactive changes of bronchial mucosa, and no fibrotic changes in the long-term observation.

Maladies respiratoires chroniques et tabagisme

Chronic respiratory diseases related to tabagism Chronic obstructive lung diseases (COPD) — including chronic bronchitis and emphysema — are an important and increasing public health problem, in which cigarette smoking has been identified as the main responsible factor. Clinical and epidemiological investigations have indicated a strong dose-response relation between COPD and the number of cigarettes smoked per day, the earliness of smoking initiation and the depth of smoke inhalation. In addition, passive inhalation of tobacco smoke may have adverse effects on the respiratory function in children and adolescents, particularly in asthmatics. Experimental studies have demonstrated that tobacco smoke induced inflammatory changes in bronchial mucosa, with ciliary dysfunction and excessive mucus secretion, favouring bacterial colonization and bronchial infection. In the lower respiratory tract of smokers, alveolar macrophages demonstrate many metabolic and functional alterations, with increase in superoxide anion production, neutrophil chemotactic activity and protease secretion, leading to an imbalance between proteases, especially elastase, and alpha 1 protease inhibitor. These changes in alveolar macrophage activities result in alveolar wall damage and enlargement of the distal air spaces. Further research is needed to identify the effects of tobacco smoke components on the respiratory tract, and to evaluate preventive approaches.

Immunohistochemical characteristics of proliferative and metaplastic lesions in bronchial mucosa.

To elucidate the characteristics of metaplastic changes of bronchial mucosa, the distribution of four epithelial antigens and two subtypes of enolases was studied immunohistochemically. The authors classified the metaplastic changes into three types: basal cell hyperplasia, stratification, and squamous metaplasia. Secretory component (SC) was detected in all lesions with stratification and in three of ten lesions of squamous metaplasia. Epithelial membrane antigen (EMA) was localized not only on the luminal surfaces but also among the stratified layers of metaplastic epithelium. No carcinoembryonic antigen (CEA) was detectable in normal epithelium, whereas almost all metaplastic lesions had both nonspecific cross-reacting antigen (NCA) and CEA immunoreactivity. In normal mucosa, basal cells were strongly positive for alpha-enolase but negative for gamma-enolase, and columnar cells expressed both enolases. In areas of metaplasia, alpha-enolase was present throughout the layer, but gamma-enolase was absent. These immunohistochemical findings suggest that metaplastic squamous epithelial cells have glandular differentiation and that several biochemical and metabolic aberrations occur during the process of metaplasia.