Effects of increased ambient pressure on mucociliary clearance have been poorly investigated. The effects of increasing pressures on ciliary beat frequency (CBF) of guinea-pig tracheal rings were ...studied in vitro. Increased pressures of 25 and 100 kPa induced a significant and equivalent enhancement of CBF from 30 min after the pressure increase. The increase in CBF observed after a pressure increase of 50 kPa (inspiratory oxygen fraction = 21%), was significantly greater than that observed with an equivalent oxygen tension at atmospheric pressure, i.e. with a gas mixture containing 30% oxygen. Addition of N(G)-nitro-L-arginine methylester (L-NAME) inhibited the enhancement in CBF observed after the 25 kPa pressure increase. Addition of L-arginine reversed the effect of L-NAME. These results demonstrate that a pressure increase applied to tracheal rings, in vitro, induces an enhancement of ciliary beat frequency and that generation of nitric oxide may be involved in this ciliary stimulation.
In nasal polyps, constantly associated with chronic inflammation, frequent epithelial morphological changes (squamous metaplasia, secretory hyperplasia) suggest a dysregulation of epithelial cell ...proliferation. Cell proliferation in nasal respiratory epithelium was therefore evaluated in nasal polyposis. In 20 patients, we compared cell proliferation in mucosa from the inferior turbinate to these in nasal polyps using two methods: Flow cytometry analyzing first the ploidy and the percentage of S-phase cells (propidium iodide DNA labeling), secondly the percentage of Ki-67-labeled cells and the green fluorescent index (fluorescein-conjugated anti-human Ki-67 antigen labeling, and thirdly the percentage of Ki-67-labeled cells being in S-phase. Immunohistochemistry, quantifying the expression of Ki-67 antigen in the epithelium permitting to calculate a Ki-67 index. All cell-populations studied were diploid. Percentages of S-phase cells, Ki-67-labeled cells, Ki-67 labeled cells being in the S-phase and green fluorescence index was significantly higher in nasal polyps than in mucosa Ki-67 index were significantly higher in nasal polyps than in mucosa in the epithelium. Epithelial cell proliferation which is therefore increased in nasal polyp could play an important role in nasal polyposis pathogenesis and its relationships with inflammation can be suggested.
Objective/Hypothesis Through human leukocyte antigen–DR (HLA‐DR) and intercellular adhesion molecule‐1 (ICAM‐1) expression, nasal epithelial cells could actively participate in the chronic ...inflammation and eosinophil infiltration observed in nasal polyps. The objective of the study was to evaluate HLA‐DR and ICAM‐1 expression in polyp epithelium and in a culture model of polyp epithelial cells allowing ciliated and secretory differentiation.
Study Design Prospective non‐randomized controlled in vitro study.
Methods The in vitro HLA‐DR and ICAM‐1 expression was studied under basal conditions or after exposure to interferon‐γ, transforming growth factor‐β1, lipopolysaccharide, dexamethasone, or cetirizine. HLA‐DR and ICAM‐1 expression was investigated in situ by immunohistochemical staining of polyps and in vitro by immunofluorescent staining of cell cultures. HLA‐DR and ICAM‐1 were localized in cultured cells by confocal microscopy. Cultured cells expressing HLA‐DR and ICAM‐1 were quantified by flow cytometry.
Results Both HLA‐DR and ICAM‐1 showed significant immunostaining of nasal polyp epithelium. In nasal polyp epithelial cell cultures, less than 5% of cells were positive for HLA‐DR whereas 40% were positive for ICAM‐1 at day 3. In vitro, HLA‐DR was mainly located in the cytoplasm and ICAM‐1 predominated on the apicolateral cytoplasmic membrane. Comparison of in situ and in vitro results showed that well‐differentiated and poorly differentiated cells predominantly expressed HLA‐DR and ICAM‐1, respectively. Interferon‐γ significantly increased HLA‐DR and ICAM‐1 expression, whereas transforming growth factor‐β1 significantly decreased HLA‐DR expression and lipopolysaccharide significantly increased ICAM‐1 expression.
Conclusion HLA‐DR and ICAM‐1 epithelial expression in nasal polyps in situ and in vitro and their in vitro modulation reinforce the active role of epithelial cells in chronic inflammatory diseases of the upper airways.
Immunocytochemical studies have shown that gel-forming glycoproteins (mucins) and the bacteriolytic protein lysozyme are selectively expressed in airway mucous and serous cells, respectively. The ...mechanisms mediating this selectivity are unknown. In this study, we localized mucin and lysozyme mRNA by in situ hybridization to investigate the possibility that phenotype-specific expression of these proteins is controlled at the level of mRNA. Radiolabelled sense and antisense probes were constructed from the human tracheal mucin cDNA, HAM1 (MUC2 gene), the human small intestinal mucin cDNA, SIB139 (MUC3 gene), and the bovine tracheal lysozyme cDNA, Lys 7a. Frozen sections of human bronchus were hybridized with these probes and washed under routine conditions. Autoradiography showed that although lysozyme mRNA was strictly limited to cells expressing lysozyme, mucin mRNA was present both in mucin-expressing and mucin-non-expressing epithelial cells. This suggests that the restriction of lysozyme to serous cells is controlled at the level of mRNA (synthesis and/or degradation), whereas the restriction of mucin to mucous cells is controlled at the level of translation.
Lower pulmonary tract cell populations collected by bronchoalveolar lavages (BAL) were evaluated in three groups of immunocompromised
patients: HIV infected patients with Pneumocystis carinii (PC) ...pneumonitis (n = 22), or pneumonitis not related to PC (n =
29), and non-HIV-infected, immunocompromised patients with a PC pneumonitis (n = 18). In AIDS patients with PC pneumonitis,
the cell populations were 59.3 +/- 4.5 percent alveolar macrophages (AM), 19.6 +/- 2.5 percent lymphocytes, 14.6 +/- 4.4 percent
polymorphonuclear cells (PMN), and 10.3 +/- 3.6 percent eosinophils. In HIV-infected patients without PC pneumonitis, they
were 76.5 +/- 3.3 percent AM, 13 +/- 2.1 percent lymphocytes, 9.2 +/- 0.3 percent PMN, and 0.6 +/- 0.2 percent eosinophils,
and in non-HIV-infected, immunocompromised patients with PC pneumonitis, they were 43.9 +/- 5.7 percent AM, 30.2 +/- 4.3 percent
lymphocytes, 20.4 +/- 4.7 percent PMN, and 0.9 +/- 0.4 percent eosinophils. The most striking finding was a marked BAL eosinophilia
in AIDS patients with PC pneumonitis. The significance of this particular cellular pulmonary response to PC is not clear,
and its consequences on the lung structures and/or PC require evaluation.
Primary ciliary dyskinesia (PCD) is an autosomal recessive disease characterized by chronic sinusitis and bronchiectasis, and usually associated with hypofertility. Half of the patients present a ...situs inversus, defining the Kartagener's syndrome. This phenotype results from axonemal abnormalities of respiratory cilia and sperm flagella, i.e., mainly an absence of dynein arms. Recently, a candidate-gene approach, based on documented abnormalities of immotile strains of Chlamydomonas reinhardtii, allowed us to identify the first gene involved in PCD. Following the same strategy, we have characterized DNAI2, a human gene related to Chlamzydomonas IC69, and evaluated its possible involvement in a PCD population characterized by an absence of outer dynein arms. DNAI2, which is composed of 14 exons located at 17q25, is highly expressed in trachea and testis. No mutation was found in the DNAI2 coding sequence of the twelve patients investigated. However, ten intragenic polymorphic sites and an EcoRI RFLP have been identified, allowing the exclusion of DNAI2 in three consanguineous families.
A number of previous studies have suggested that the fat emulsion, Intralipid, might compromise human host defenses, due mainly to impairment of neutrophil functions. The aim of this study was to ...evaluate the effects of Intralipid on neutrophil chemotaxis in cancer patients receiving total parenteral nutrition including 500 ml of 20% Intralipid over 6 hours (83 ml/hr). No impairment of neutrophil chemotaxis was found during or after lipid infusion. Further investigations are necessary to determine whether, in routine clinical practice, intralipids are responsible for impairment of other neutrophil functions and whether side treatments have a protective effect for neutrophil functions.
Although respiratory changes induced by tobacco smoke have been extensively described, no study has focused on ciliary abnormalities associated with chronic smoking. Ciliary ultrastructure was ...studied in 37 adults with chronic sputum production (CSP) consisting of 13 current smokers (Group 1), 5 ex-smokers (Group 2), and 19 nonsmokers (Group 3). Five healthy nonsmokers constituted the control group (Group 4). Clinical and radiologic data and respiratory function tests were recorded. Acute respiratory infection was diagnosed by culture of tracheobronchial secretions obtained during bronchoscopy. Bronchial ciliated cells were obtained and processed for transmission electron microscopy. Within each group, the percentages of abnormal cilia were similar in patients with either chronic bronchitis or bronchiectasis and in patients with or without acute infection. The percentage of axonemal ultrastructural abnormalities (AUA) was higher in smokers (16.5% +/- 2.7%) and ex-smokers (17.5% +/- 7%) than in nonsmokers (5.2% +/- 1%) or control subjects (0.7% +/- 0.2%) (p < 0.0002). The AUA were polymorphic, characteristic of acquired ultrastructural changes. These results suggest that chronic smoking may induce an increased number of abnormal cilia which could participate in impairment of tracheobronchial clearance and which appears to be independent of the etiology of CSP.
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