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Respiratory infections and asthma
No full textClinical and experimental evidence suggests an important role for respiratory infections in the development of asthma attacks. Viral upper respiratory infections have been associated with 80% of asthma exacerbations in children and 50% of all asthma episodes in adults. Human rhinovirus has been implicated as the principal virus associated with asthma episodes. Separate studies indicate that atypical bacteria such as Chlamydia pneumoniae and Mycoplasma pneumoniae may precipitate asthma symptoms. Although not completely clarified, the intricate pathogenetic mechanisms by which viral infections promote asthma attacks have been extensively investigated in recent years. By contrast, it has not yet been established whether atypical bacterial infections are an epiphenomenon or a pathogenic event in asthma
GLOBULE LEUCOCYTES: AN ULTRASTRUCTURAL ANALYSIS OF THE HUMAN INTRAPULMONARY AIRWAYS IN C.O.P.D. PATIENTS AND NORMAL SUBJECTS
No full textIn the current study we describe the presence and the ultrastructure of globule leucocytes (GL) in the respiratory epithelium of the lobar bronchi of eight adult individuals (1 normal, plus 7 C.O.P.D.). This peculiar type of migratory cell was previously described in rat trachea (Kent, 1966; Jeffery and Reid, 1975), in dog bronchial epithelium (Frasca et al., 1968), in calf bronchoalveolar lavage (Coles et al., 1987) and human upper respiratory tract (Baert and Frederix, 1985). We are therefore the first who describe the presence of GL in the bronchial mucosa of the human lower respiratory tract.
The T.E.M. analysis of mucosal bioptic specimens obtained through fiberoptic bronchoschopy from the human intrapulmonary bronchial epithelium revealed the presence of cells characterized by intracytoplasmic granules showing a homo¬geneous electrondense matrix, nevertheless considerably variable in size, shape and number. According to such peculiar morphological features, these cellular elements were classified as GL.
The origin of these cells in the airway epithelium is uncertain, but the presence of granulated cells both in the basal layer of the epithelium, in the subepithelial connective tissue and in the submucosal blood vessels, suggest that GL may result from the possible transformation-maturation of granulated leucocytes.
The current, morphological, study is the starting point for next studies on GL possible role and involvement both in the physiology and physiopathology of the human respiratory function
Fattori modificanti la suscettibilità delle vie aeree alle infezioni da Rinovirus Umano.
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