Histological and ultrastructural observations on the development of the lung of the fetal pig

Lungs of fetal pigs having gestational ages ranging from 80 to 115 days were examined histologically and by electron microscopy. At 80 days bronchial epithelium was ciliated but bronchiolar cells were not and bronchial mucosal glands were absent. Peripheral regions consisted predominantly of mesenchymal tissue with glandular alveoli. 92 days marked the transition from the immature to the more mature lung type. Bronchial glands appeared and began to grow from the epithelium into the lamina propria, bronchiolar epithelial cells acquired cilia, and alveoli were becoming irregular in shape and had thinner interalveolar septa. Close contact between capillaries and alveolar epithelium established the blood-air barrier at many points. Differentiation of alveolar epithelium into types I and II pneumonocytes occurred at this stage and lamellated osmiophilic inclusion bodies were present in type II cells for the first time. The number of lamellated bodies increased progressively to term at 115 days.     

Enhanced endocrine response to novel environment stress and endotoxin in Lurcher mutant mice

Although electron microscopy no longer enjoys the important role in the diagnosis of interstitial lung diseases that it had in the 1960s and 1970s, it remains an important adjunct in the differential diagnosis of certain pulmonary diseases. Examples include various manifestations of systemic lupus erythematous pneumonitis, in which the presence of tubuloreticular structures and electron-dense deposits are useful for diagnosis; immotile cilia disorders, in which qualitative and now quantitative studies of the cilia of respiratory epithelial cells can help to establish the diagnosis; infections by viruses and other subcellular microorganisms as shown by the role played by electron microscopy in the initial diagnosis of the Hantavirus pulmonary syndrome; pneumoconioses, in which, in conjunction with elemental analysis probes, scanning electron microscopy is of critical importance in establishing the presence of offending foreign compounds in lung tissue or fluids; pulmonary fibrilloses, such as amyloidosis, light chain disease, and fibrillary glomerulonephritis, affecting the lung; and cases of alveolar proteinosis or Langerhans cell granulomatosis diagnosed from fluids such as bronchoalveolar lavages or small tissue samples. As important, electron microscopy remains of enormous usefulness in the study of early structural events leading to the pathogenesis of diseases. For example, recent uses of the technique have focused on the alveolar-capillary wall damage induced by alveolitis in hypersensitivity pneumonitis and sarcoidosis. In summary, electron microscopy remains a useful method in the study and diagnosis of some interstitial lung diseases, but because of its expense it is incumbent on the clinician to use good judgment in the selection of cases and diseases for study by this method.     

Chronic bronchitis--alterations of the bronchial mucosa

The mucociliary transport system is usually an important defense system which protects the body against a variety of noxious agents. Reactions of the bronchial mucosa to chronic infections are seen in the ciliated cells, the amount of globlet cells, in modifications of the basement membrane underlying the bronchial epithelium and an altered percentage of inflammatory cells. In ciliated cells the following atypia can be seen: thickening of the ciliar membrane, swollen cilia, formation of compound cilia, disarrangement of microtubules. Common alterations of the basement membrane are: increased diameter of the basement membrane zone, inhomogeneous staining pattern of the basement membrane zone, formation of cytoplasmatic protrusions, formation of double layers of the basement membrane and increased number of cytoplasmatic bound vesicles. Structural abnormalities of the basement membrane will lead to disturbances of the zone of transition and have to be interpreted as a sign of disregulation in the process of diffusion and resorption. The inflammatory response of the epithelium during chronic bronchitis and asthma shows many similarities. The bronchial epithelium has a specific reaction pattern which supports the response against different noxious agents. So all findings have to be interpreted as unspecific pathological changes. All alterations may show different degrees of severity and are dependent on individual pattern and the severity of chronic process. Electronmicroscopical examinations in combination with lightmicroscopical findings and immuno-histochemistry and seen in context with clinical data help to understand the mechanism of the inflammatory process.     

Interstitial lung disease more than 40 years after a 5 year occupational exposure to talc

A 62 yr old woman was initially diagnosed with sarcoidosis until a thoracoscopic biopsy revealed the presence of numerous birefringent particles in fibrotic areas of the centrilobular lung zones. These particles were examined by electron microscopy and X-ray spectrometry and characterized as impure talc. Further inquiry into her occupational history revealed that she had worked from the age of 14-18 yrs in a factory making rubber hoses, where she had had an intense exposure to talc. There was no evidence of silicosis or asbestosis, and other significant causes of interstitial lung disease were excluded. This case emphasizes the importance of a thorough occupational history, which may reveal a remote and forgotten exposure to a significant cause of interstitial lung disease. Although this presentation of talcosis is unusual, this case suggests that even a relatively short, but presumably intense exposure to talc more than 40 yrs previously may be a cause of progressive lung fibrosis.     

Clearance of lead-212 ions from rabbit bronchial epithelium to blood

The absorption of 212Pb ions from bronchial epithelium to blood has been investigated in anaesthetized rabbits. The 212Pb ions were introduced by intubation either into the trachea or into smaller, more distal bronchi. Removal from lung was followed by external gamma-counting. Mucociliary clearance to the GI tract was blocked by tracheostomy. Two distinct phases of clearance from bronchial epithelium to blood were observed. Approximately 20% of deposited 212Pb is rapidly absorbed with a half-time of about 4 min, the remainder with a biological half-time of about 9 h, irrespective of the site of instillation in the bronchial tree. Two hours after deposition, the 212Pb remaining in lung was found to be partitioned between mucus and the bronchial epithelium, with a substantial but minor fraction in the epithelium. Uptake of 212Pb in the skeleton was estimated to be about 20% of the 212Pb entering the blood circulation. Removal by the kidneys, at 25%, was comparable with skeletal uptake. These results are compared with previously published work using rodents, dogs and man which demonstrated either rapid or slow absorption but not both phases occuring together.     

Lessons from human arteries: how to design a gene therapy strategy for treatment of cardiovascular disease

The histological and ultrastructural characteristics of an adenocarcinoma of the lung are described in an about 16-year-old female Steller sea lion with a 1.5 month history of cough and anorexia. The animal had multiple neoplastic nodules in the lungs and diaphragmatic pleura. The bronchial and mediastinal lymph nodes were replaced by neoplastic tissue, and there were several metastatic lesions in the liver and spleen. The lung tumor was characterized by accumulations of encapsulated lesions with central necrosis, and the neoplastic cells showing a papillary growth pattern produced small amounts of mucin. Ultrastructurally, some cells contained basal bodies, and cilia were rarely seen. This neoplasm was considered to be of ciliated bronchial or bronchiolar epithelium origin.     

Molecular damage in the bronchial epithelium of current and former smokers

BACKGROUND: Most lung cancers are attributed to smoking. These cancers have been associated with multiple genetic alterations and with the presence of preneoplastic bronchial lesions. In view of such associations, we evaluated the status of specific chromosomal loci in histologically normal and abnormal bronchial biopsy specimens from current and former smokers and specimens from nonsmokers. METHODS: Multiple biopsy specimens were obtained from 18 current smokers, 24 former smokers, and 21 nonsmokers. Polymerase chain reaction-based assays involving 15 polymorphic microsatellite DNA markers were used to examine eight chromosomal regions for genetic changes (loss of heterozygosity [LOH] and microsatellite alterations). RESULTS: LOH and microsatellite alterations were observed in biopsy specimens from both current and former smokers, but no statistically significant differences were observed between the two groups. Among individuals with a history of smoking, 86% demonstrated LOH in one or more biopsy specimens, and 24% showed LOH in all biopsy specimens. About half of the histologically normal specimens from smokers showed LOH, but the frequency of LOH and the severity of histologic change did not correspond until the carcinoma in situ stage. A subset of biopsy specimens from smokers that exhibited either normal or preneoplastic histology showed LOH at multiple chromosomal sites, a phenomenon frequently observed in carcinoma in situ and invasive cancer. LOH on chromosomes 3p and 9p was more frequent than LOH on chromosomes 5q, 17p (17p13; TP53 gene), and 13q (13q14; retinoblastoma gene). Microsatellite alterations were detected in 64% of the smokers. No genetic alterations were detected in nonsmokers. CONCLUSIONS: Genetic changes similar to those found in lung cancers can be detected in the nonmalignant bronchial epithelium of current and former smokers and may persist for many years after smoking cessation.     

Non-fibrous inorganic particles in bronchoalveolar lavage fluid of pottery workers

AIM: To study the actual exposure of pottery workers to silica particles, as their risk of silicosis is potentially high because of the presence of inhalable crystalline silica particles in the workplace. METHODS: Nine pottery workers underwent bronchoalveolar lavage. The recovered fluid was analysed for cytological and mineralogical content by analytical transmission electron microscopy. The data were compared with those obtained from a control group composed of seven patients with sarcoidosis and six patients with haemoptysis. RESULTS: Cytological results showed a similar profile in exposed workers and controls, whereas in patients with sarcoidosis a lymphocytic alveolitis was found. Microanalysis of the particulate identified the presence of silicates, CRSs, and metals. Pottery workers had higher numbers of total particles and CRSs, and had a higher silicate/metal ratio. In five workers, the presence of zirconium silicate was also detected. Patients with sarcoidosis had the lowest number of particles, and an inverted silicate/metal ratio. CONCLUSION: Microanalysis by transmission electron microscope can provide useful information to assess occupational exposure to dusts.     

Tumour markers in the diagnosis of bronchial carcinoma: new options using fuzzy logic-based tumour marker profiles

The diagnosis of lung cancer and early knowledge of its histological type are very important; however, this is still a difficult subject for the physician. The aim of this study was to improve the diagnostic efficiency of tumour markers in the diagnosis of bronchial carcinoma by mathematical evaluation of a tumour marker profile employing fuzzy logic modeling. A panel of five tumour markers, including CYFRA 21-1, CEA, NSE, and five additional parameters was determined in 281 patients with confirmed primary diagnosis of bronchial carcinoma of different histology and stage. A further 131 persons, who had acute and chronic benign lung diseases, served as a control group. A classificator was developed using a fuzzy-logic rule-based system. The diagnostic value of the combined tumour markers was significantly better than that of the individual markers and of a combination of CYFRA 21-1, CEA, and NSE. The discrimination of malignant vs benign diseases was realized with a sensitivity of 87.5% and specificity of 85.5%. The rate of correct classification of small-cell vs non-small-cell lung carcinoma was 90.6% and 91.1%, respectively; for squamous cell carcinoma vs adenocarcinoma it was 76.8% and 78.8%, respectively. Our detailed analysis has shown that the fuzzy logic system improves diagnostic accuracy up to a rate of 20%, especially in early stages and in patients with all marker levels in the grey area. Our concept proved to be more powerful than measurement of single markers or the combination of CEA, CYFRA 21-1, and NSE. Its use may help in distinguishing between malignant and benign disease and make it possible to define different subgroups of patients earlier in the course of their disease.     

Immunoglobulin content in the bronchial washings of patients with benign and malignant pulmonary disease

The bronchial washings of 58 patients with benign and neoplastic conditions involving the lungs were evaluated for immunoglobulin content. Levels in the washings from the diseased lung were compared with those from the normal contralateral lung. In normal patients and those with either bilateral inflammatory diseases or unilateral bronchiectasis or tuberculosis, the mean variation in igA/K and igG/K ratios between diseased and uninvolved lungs was minimal. In unilateral pneumonitis, however, igG/K was markedly elevated (P less than 0.01). Significant changes in the igA/K occurred on the affected side in patients with cancer. In the group with squamous-cell cancer. the mean elevation was 4.6 times that of contralateral lung (P less than 0.005), whereas with adenocarcinoma and undifferentiated carcinoma, the rise was 6.4 and 2.8 times, respecitvely (P less than 0.01 and P less than 0.01). Thus, carcinoma appears to alter local immunoglobulin production in the affected lung as compared to its normal counterpart. (N Engl J Med 295:694-698, 1976).     

Cystic fibrosis: effects of serum factors on mucus secretion

The effects of serum from children with cystic fibrosis and from normal children on the mucus-secreting, ciliated epithelium have been investigated in vitro using explanted tissue from rabbit lung. By optical and scanning electron microscopy, a sequence of structural changes is observed after incubation with cystic fibrosis serum; this sequence does not occur with normal serum. The earliest changes involve swelling of the goblet cells, with subsequent discharge of mucus onto the epithelial surface. This is followed by disruption of the normally rapid and synchronized ciliary activity. Mucus gradually extends over the surface entangling cilia. Finally, some shedding of ciliated cells occurs from the epithelium. These findings suggest that factors in cystic fibrosis serum cause discharge of mucus leading to a disturbance of the normal ciliary activity in the rabbit lung. It is postulated that such changes result in dysfunction of the mucociliary clearance mechanism and that this dysfunction may be a contributory factor to the pathogenesis of lung disease.     

Increased epidermal growth factor receptor expression in metaplastic bronchial epithelium

Epidermal growth factor receptor (EGFr) is expressed in human bronchial epithelial cells, and non-small cell lung cancers express increased EGFr. Squamous metaplasia of the bronchial epithelium occurs in chronic smokers and is considered an early premalignant change. In this study, EGFr expression was examined in biopsies of histologically normal and metaplastic bronchial tissues obtained from 69 smokers who were enrolled in a randomized placebo-controlled chemoprevention trial. This trial tested the effects of 6 months of treatment with 13-cis retinoic acid (13cRA) on bronchial metaplasia. EGFr expression was examined as a marker of bronchial metaplasia and response to 13cRA treatment. In bronchial biopsies obtained from patients in this study, EGFr expression was higher in metaplastic biopsies than in normal biopsies (P = 0.02). Smoking cessation during treatment correlated with reduced metaplasia (P < 0.001) and EGFr expression (P = 0.02), but multivariate analysis suggested that this effect of smoking cessation on EGFr expression was dependent upon reversal of bronchial metaplasia. 13cRA treatment did not alter EGFr expression (P = 0.23). Baseline EGFr expression levels in metaplastic biopsies did not predict metaplasia reversal. This study demonstrated that increased EGFr expression is a biomarker of bronchial metaplasia, but it did not support the hypothesis that EGFr is a biomarker of retinoid response in lung cancer chemoprevention trials.     

Ultrastructure of bronchial blood vessels in chronic inflammation and endobronchial laser therapy

Structural metabolic changes in the biopsies of the large bronchi mucous membrane were studied in 99 patients with chronic lung diseases. Progressing sclerosis of the connective tissue stroma resulted in the reduction of endotheliocyte metabolism which usually represent plastically active zone of the strom. This considerably influences basal cell proliferation resulting in changes of differentiation in bronchial epithelium. Endobronchial laser therapy induces proliferative and metabolic processes in the tunica propria of the mucous membrane. Congestion, intensive leucodia pedesis, leucocytic infiltrates and granulations develop in the mucous membrane, proliferative and metabolic activity of endotheliocytes and stromal cells increases this resulting in formation of fine fibrillar connective tissue.     

Histopathologic and molecular alterations in bronchial epithelium in habitual smokers of marijuana, cocaine, and/or tobacco

BACKGROUND: Tobacco smoking has been observed to cause molecular alterations in bronchial epithelium that antedate the development of lung carcinoma. The rising prevalence of marijuana and cocaine use among young adults in the United States prompted us to investigate whether similar molecular and histopathologic alterations occur in habitual smokers of marijuana and/or cocaine who may or may not also smoke tobacco. METHODS: Bronchoscopy was performed in 104 healthy volunteer subjects, including 28 nonsmokers and 76 smokers of one or more of the following substances: marijuana, tobacco, and/or cocaine. Bronchial mucosa biopsy specimens and brushings were analyzed for histopathologic changes, for immunohistopathologic expression of intermediate or surrogate end-point markers that are linked to an increased risk of cancer (Ki-67 [a marker of cell proliferation], epidermal growth factor receptor, p53, Her-2/neu [also known as erbB-2 and ERBB2], globular actin, and abnormal DNA ploidy). Reported P values are two-sided. RESULTS: Smokers of any one substance or of two or more substances exhibited more alterations than nonsmokers in five to nine of the 10 histopathologic parameters investigated (all P < .05), and they exhibited more molecular abnormalities than nonsmokers. Differences between smokers and nonsmokers were statistically significant (all P < or = .01) for Ki-67, epidermal growth factor receptor, globular actin, and DNA ploidy. There was general agreement between the presence of molecular abnormalities and histopathologic alterations; however, when disagreement occurred, the molecular abnormalities (e.g., Ki-67 and epidermal growth factor receptor) were more frequently altered (all P < or = .01). CONCLUSIONS: These findings suggest that smoking marijuana and/or cocaine, like tobacco smoking, exerts field cancerization effects on bronchial epithelium, which may place smokers of these substances at increased risk for the subsequent development of lung cancer.     

Inflammatory cells in the bronchial glands of smokers with chronic bronchitis

To characterize the inflammatory process in the bronchial glands of smokers with chronic sputum production, we examined lobar bronchi from 18 subjects undergoing lung resection for localized pulmonary lesions, all with a history of cigarette smoking. Nine of the subjects had symptoms of chronic bronchitis and chronic airflow obstruction, and nine were asymptomatic, with normal lung function. The number of neutrophils, eosinophils, mast cells, macrophages, CD4+ and CD8+ T-lymphocytes, and the ratio of CD4+ to CD8+ cells were assessed in the bronchial glands, epithelium, and submucosa. Cells were identified through immunohistochemistry. Smokers with symptoms of chronic bronchitis had an increased number of neutrophils (p = 0.01) and macrophages (p = 0.03) and a decreased CD4+/CD8+ ratio (p = 0.01) in the bronchial glands as compared with asymptomatic smokers. Chronic bronchitic smokers also had an increased number of epithelial neutrophils (p = 0.04), whereas the numbers of macrophages and CD4+ and CD8+ T-lymphocytes in the epithelium and submucosa were similar in the two groups of smokers. No differences in numbers of eosinophils or mast cells were observed between bronchitic and asymptomatic smokers in any of the compartments examined. In conclusion, smokers with chronic sputum production have an increased infiltration of neutrophils and macrophages and an increased proportion of CD8+ T-lymphocytes in their bronchial glands, supporting the important role of bronchial-gland inflammation in the pathogenesis of chronic bronchitis.     

Study of the morphology of the cell walls of some strains of lactic acid bacteria and related species

OBJECTIVE: To examine Mycoplasma ovipneumoniae for presence of a capsule and its potential role in adherence. SAMPLE POPULATION: 17 isolates of M ovipneumoniae and 2 isolates of M arginini, recovered from sheep with respiratory tract disease. PROCEDURE: Mycoplasmas were cultured in modified Fills broth medium, ovine fetal lung cells, or ovine tracheal ring explants. Pelleted mycoplasmas or ring cultures infected with mycoplasmas were treated with ruthenium red or polycationic ferritin and visualized by transmission electron microscopy. Reactivity of several lectins with the mycoplasmas was studied by use of a microtitration plate agglutination test. RESULTS: Electron microscopy revealed a large number of M ovipneumoniae cells covered with an electron dense-stained amorphous material suggesting that it was a capsule. Multiple passages of the microorganisms in modified Friis broth medium decreased thickness of the capsule, but not percentage of cells encapsulated. Marked differences were observed when M ovipeumoniae isolates grown in modified Friis broth medium or co-cultured with ovine fetal lung cells were compared for capsular thickness or percentage of encapsulation. In thin sections of ruthenium red-stained tracheal ring cultures, the mycoplasmas appeared to be in close contact with cilia through their capsule. All isolates of M ovipneumoniae reacted strongly with wheat germ agglutinin lectin. CONCLUSIONS: Mycoplasma ovipneumoniae produces a polysaccharide capsule with variable thickness that is dependent on culture conditions and strain. Morphologic observations suggest that this capsule facilitates adherence of the organism to ciliated epithelium.     

Three-dimensional structure of the rat pancreatic duct in normal and inflammated pancreas

We observed the corrosion casts of the Wistar rats' pancreatic ducts with scanning electron microscopy (SEM), and their conventionally fixed pancreatic tissue with SEM and transmission electron microscopy (TEM). These findings revealed the following facts about the three-dimensional structure of pancreatic duct. (1) The interlobular and intralobular ducts branch like a tree, and the intercalated ducts wind and fork into two branches, although parts of the intercalated ducts anastomose with each other. The intercellular secretory canaliculi extend from the central lumina, which run straight through the center of the acini, finally approaching close to the basement membranes of acini. (2) The lumina of pancreatic ducts (i.e., the interlobular up to the intercalated ducts) are cylindric and have smooth surfaces. The luminal surface of each epithelial cell, however, is decorated by numerous microvilli and a single cilium. The length of the latter tends to be short in proportion to the diameter of pancreatic duct. Moreover the epithelial cell surfaces, which border each central lumen, have various densities of microvilli. (3) The intraductal cilium core is provided with nine microtubules, which is different from the number of microtubules encountered within the cilium core of uterine tube or bronchial epithelium. The number of microtubules in the cross-sectioned intraductal cilia decreases toward the distal portion of cilia. SEM and TEM observations on WBN/Kob rats' pancreatic ducts suggest that increased pancreatic ductal pressure causes the helical shape of the pancreatic ductal lumen. Such a helical form might also be caused by the protrusion of epithelial cell boundaries into their lumen and the hypertrophy and hyperplasia of epithelial cells, thus leading to the formation of numerous depressions equipped with elongated cilia.     

Induced expression of the Candida albicans multidrug resistance gene CDR1 in response to fluconazole and other antifungals

Squamous cell carcinoma (SCC) antigen (Ag) present and expressed in normal epithelium and epithelial tissues is used primarily as tumor marker of SCC of the uterine cervix. In this review, we considered factors interfering in vitro with the collection of samples and assay procedures, benign and malignant nongynecological diseases which may be the cause of elevated serum levels of SCC Ag. Contamination with skin or saliva strongly influences SCC Ag levels. SCC Ag is elevated in several benign lesions, including pulmonary (tuberculosis, adult respiratory distress syndrome, pulmonary infiltration with eosinophilia, sarcoidosis, bronchogenic cyst) and skin (eczema, pemphigus, erythroderma epidermitis, psoriasis) diseases. Elevations are observed in SCC malignancies of the head and neck, esophagus, skin, lung, urothelium, anal canal and vulva.     

A diffuse form of pulmonary silicosis in foundry workers

Pulmonary silicosis usually is characterized by typical hyalinized, concentric nodules as seen under the microscope and in the corresponding roentgenogram. In the case of three foundry workers, lung biopsy specimens contained no nodules. The chest roentgenograms were not suggestive of silicosis. Examination of the biopsy tissue by scanning electron microscopy and energy dispersive x-ray analysis (EDXA) revealed significant (P less than .05) amounts of silicon in the thickened fibrous tissues of septa, pleura, and around blood vessels, enough to permit the diagnosis of silicosis. All three patients had severe functional impairment. It is not clear at this time what factors were responsible for a diffuse distribution of silicon in these cases.     

Systemic embolism in a renal transplant patient. Echocardiographic demonstration of bronchial carcinoma with intracardiac invasion

A 45 year old female renal transplant patient was admitted for subacute ischaemia of a lower limb. Echocardiography was performed and showed the presence of bronchial carcinoma with intracardiac invasion. The tumour was confirmed by thoracic computerised tomography and by bronchoscopy. Histological investigation of bronchial biopsies and of the arterial embolism extracted at surgery showed large cell malignant disease. The tumour partially responded to chemotherapy and the patient survived for 5 months. Extension of a bronchial carcinoma to the left atrium is a classical complication in autopsy reports but rarely a source of systemic embolism. Echocardiographic diagnosis of this condition is very rare. The incidence of malignant diseases is higher in renal transplant patients than in the general population but this has not been verified for bronchial carcinoma. Echocardiography played an essential role in this case, detecting the tumour and its extension, indicating a poor prognosis and guiding treatment.