Small bronchiolar histopathological changes related to prolonged diabetes / Pequeños cambios histopatológicos bronquiolares relacionados con la diabetes prolongada

SUMMARY: Diabetes mellitus increases the risk of developing chronic obstructive pulmonary disease (COPD). The small bronchiole is a prominent site of airflow obstruction that causes increased airway resistance in patients with the COPD. Therefore, the histological and ultrastructural changes in small bronchioles in streptozotocin (STZ)-induced chronic diabetes were determined. Twenty-four weeks after STZ induction, rats were sacrificed, and the right and left lungs were collected for examination by light and electron microscopy. The alterations to the small bronchioles were the same in both lungs of these diabetic rats. The bronchiolar epithelial cells, both ciliated and secretory club cells, showed pyknotic nuclei and damaged cytoplasmic organelles. Increased thickening of the bronchiolar wall occurred in diabetic rats due to smooth muscle layer thickening, inflammatory cell infiltration, and increased numbers of myofibroblasts with collagen deposition.These results indicated that chronic diabetes caused extreme damage to small bronchioles, which may lead to chronic small airway obstruction and ultimately increase the likelihood of COPD progression. This basic knowledge provides a better understanding of the progression of pathogenesis in the small airways of patients with prolonged diabetes.

RESUMEN: La diabetes mellitus aumenta el riesgo de desarrollar enfermedad pulmonar obstructiva crónica (EPOC). El bronquiolo es un sitio prominente de obstrucción del flujo de aire que causa una mayor resistencia de las vías respiratorias en pacientes con EPOC. Por lo tanto, se determinaron los cambios histológicos y ultraestructurales en los bronquiolos en la diabetes crónica inducida por estreptozotocina (STZ). 24 semanas después de la inducción de STZ, se sacrificaron las ratas y se analizaron los pulmones derecho e izquierdo por microscopía óptica y electrónica. Las alteraciones de los pequeños bronquiolos fueron las mismas en ambos pulmones de estas ratas diabéticas. Las células epiteliales bronquiolares, tanto ciliadas como secretoras, mostraban núcleos picnóticos y orgánelos citoplasmáticos dañados. Se produjo un aumento del engrosamiento de la pared bronquiolar en ratas diabéticas debido al engrosamiento de la capa de músculo liso, infiltración de células inflamatorias y un mayor número de miofibroblastos con colágeno. Estos resultados indicaron que la diabetes crónica causaba daño extremo a los pequeños bronquiolos, lo que puede conducir a una obstrucción crónica de las vías respiratorias pequeñas y además aumentar la probabilidad de progresión de la EPOC. Esta información proporcionará un mejor conocimiento de la patogénesis en las vías respiratorias pequeñas de los pacientes con diabetes prolongada.

Histology and scanning electron microscopy of the lower respiratory tract in the adult red fox (Vulpes vulpes) / Histología y microscopía electrónica de barrido de las vías respiratorias inferiores en el zorro rojo adulto (Vulpes vulpes)

The study was conducted on a total of three adult healthy freshly killed red foxes of both sexes weighing about 4-6 kg collected from Abou Rawwash, Giza, Egypt. The wall of trachea and bronchi formed of mucosa, submucosa and adventitia. The mucosa formed of pseudostratified columnar epithelium and lamina propria. The respiratory epithelium composed of tall columnar ciliated, goblet cells, basal cells, and neuroendocrine cells. Goblet cells account for about 20 to 30% of cells in the more proximal. Basal cells are relatively small triangular cells whose bases are attached to the basement membrane. The primary bronchiole is lined by simple columnar nonciliated to cuboidal epithelium containing some bronchiolar exocrine cells and some goblet cells. Neuroendocrine cells constitute about 4 to 5% of bronchial epithelial cells, attached at their bases to the basement membrane and have tapering apices. The lamina propria consists principally of a network of capillaries, a meshwork of connective tissue fibers continuous with the basement membrane. The submucosa formed of connective tissue elements and blood vessels and devoid of Tracheobronchial glands in red fox. The adventitia contain tracheal cartilage and muscle in trachea and bronchial cartilages and muscles in bronchi. Tracheal muscle is transverse bundles attached to the outer perichondrium. In the bronchi, muscle is organized in transverse bundles close to the epithelium adjacent to the lamina propria and longitudinal bundles close to the cartilages. Alveoli are demarcated by septa composed of a continuous layer of epithelial cells overlying a thin interstitium. The epithelial cells consist principally of type I and type II pneumocytes. SEM revealed that, the mucosal surface of both trachea and bronchi was completely covered by cilia. There were few glandular openings or goblet cell.

El estudio se realizó en tres zorros rojos adultos sanos, recién fallecidos, de ambos sexos, con un peso aproximado 4,6 kg recogidos de Abou Rawwash, Giza, Egipto. La pared de la tráquea y los bronquios estaban formados por mucosa, submucosa y adventicia. La mucosa estaba formada por un epitelio estratificado y lámina propia. El epitelio respiratorio ciliado compuesto de células caliciformes, células basales y células neuroendocrinas. Las células calciformes representaban alrededor del 20 al 30% de las células más proximales. Las células basales eran células triangulares relativamente pequeñas cuyas bases están unidas a la membrana basal. El bronquiolo principal está cubierto por un epitelio columnar simple no ciliado que contiene algunas células exocrinas bronquiolares y células caliciformes. Las células neuroendocrinas constituyen aproximadamente 4 a 5% de las células epiteliales bronquiales, unidas en sus bases a la membrana basal y tienen ápices de ahusamiento. La lámina propia consiste principalmente en una red de capilares, una malla de fibras de tejido conectivo continuo con la membrana basal. La submucosa formada por elementos del tejido conectivo y vasos sanguíneos y escasas glándulas traqueobronquiales. La capa adventicia contiene cartílago traqueal y muscular en la tráquea, y los bronquios cartílagos y músculos. En los bronquios, el músculo está compuesto de haces transversales cercanos al epitelio próximo a la lámina propia y haces longitudinales cerca de los cartílagos. Los alvéolos están delimitados por tabiques compuestos de una capa continua de células epiteliales que recubren un intersticio delgado. Las células epiteliales se componen principalmente de neumocitos tipo I y tipo II. El MEB reveló que la superficie de la mucosa de la tráquea y los bronquios estaba completamente cubierta por cilios. Se observaron pocas aberturas glandulares o células caliciformes.

Pathological and ultrastructural analysis of surgical lung biopsies in patients with swine-origin influenza type A/H1N1 and acute respiratory failure

BACKGROUND: Cases of H1N1 and other pulmonary infections evolve to acute respiratory failure and death when co-infections or lung injury predominate over the immune response, thus requiring early diagnosis to improve treatment. OBJECTIVE: To perform a detailed histopathological analysis of the open lung biopsy specimens from five patients with ARDS with confirmed H1N1. METHODS: Lung specimens underwent microbiologic analysis, and examination by optical and electron microscopy. Immunophenotyping was used to characterize macrophages, natural killer, T and B cells, and expression of cytokines and iNOS. RESULTS: The pathological features observed were necrotizing bronchiolitis, diffuse alveolar damage, alveolar hemorrhage and abnormal immune response. Ultrastructural analysis showed viral-like particles in all cases. CONCLUSIONS: Viral-like particles can be successfully demonstrated in lung tissue by ultrastructural examination, without confirmation of the virus by RT-PCR on nasopharyngeal aspirates. Bronchioles and epithelium, rather than endothelium, are probably the primary target of infection, and diffuse alveolar damage the consequence of the effect of airways obliteration and dysfunction on innate immunity, suggesting that treatment should be focused on epithelial repair.

Disquinesia ciliar primaria: su presentación en Otorrinolaringología: Experiencia con 14 pacientes / Primary ciliar dyskinesia: its presentation in otolaringology: experience with 14 patients

La disquinesia ciliar primaria (DCP) es una enfermedad subdiagnosticada que suele tener manifestaciones importantes en Otorrinolaringología. Se analizan 14 pacientes en quienes el diagnóstico de DCP se basó en la persistencia de infecciones crónicas, ya sea a nivel nasosinusal u ótico. Las patologías más frecuentemente involucradas fueron la rinosinusitis crónica y la otitis media con efusión. El diagnóstico se hizo con microscopía electrónica de transmisión de mucosa bronquial. La alteración ciliar encontrada más reiteradamente fue la ausencia del brazo interno de dineína. En 6 pacientes se debió realizar cirugía endoscópica funcional de cavidades perinasales debido a una rinosinusitis crónica y, en 8, se debió colocar tubos de ventilación, por la otitis media con efusión persistente.

Ultrastructure of the tracheobronchial epithelium of the normal and formaldehyde-exposed guinea-pig

Thirty adult male guineca pigs were used in this study, fifteen taken as control, while the other fifteen were exposed to formaldehyde.The tracheobronchial epithelium of all animals were examined by means of light and electron microscopy. The tracheobronchial epithelium of the control animals was found to consist of ciliated, goblet, basal and intermediate cells. The general structure of the epithelium is suggested to provide a barrier restricting the transfer of exogenous material from the airway lumen to the blood stream. Moreover, the actively motile cilia of the ciliated cells are responsible for transport of mucus with included foreign materials to the throat where the mucus normally swallowed. The goblet cells continuously secrete mucus which formed a physical barrier between the inhaled pollutants and underlying epithelium. The results of this work suggest that, both motile cilia and secretion of correct amount of mucus with suitable vesicoelasticity are responsible for maintenance of mucociliaryy clearance. Also the intermediate cells were observed to be differentiated into goblet cells. Following formaldehyde exposure, profound general and special epithelial and submucosal changes, ranging from moderate to severe were observed within the tracheobronchial epithelium.Early after short periods of formaldehyde exposure, the structural changes in the bronchial epithelium were observed to be less severe than that of the tracheal epithelium. However, later on, with prolongation of the period of formaldehyde exposure, both trachea and bronchi were severely affected. The general epithelial changes included, 1] ulceration of the tracheobronchial epithelium which is emphasized to expose and sensitize the airway receptors to inhaled irritants which are responsible for the pathogenesis of occupational asthma. 2] proliferative changes in the form of simple hyperplasia, basal and goblet cell hyperplasia and squamous metaplasia have occurred and suggested the possibility of formaldehyde carcinogenicity 3] thickening of the basement membrane which is considered to be a protective mechanism against inhaled formaldehyde. On the other hand, the special epithelial changes were evidenced by the appearance of a great number of ciliary abnormalities and apocrine, massive mucus secretion of the goblet cells with subsequent impairment of the mucociliary clearance. Both fibrosis and airway obstruction are considered to be the latest sequlae of long term injury produced by formaldehyde exposure as indicated by the appearance of fibroblasts and smooth muscle fibers within the submucosa of tracheobronchial epithelium

Ultrastructure of the tracheobronchial epithelium of the normal and formaldehyde-exposed guinea-pig

Thirty adult male guinea pigs were used in this study, fifteen were taken as control, while the other fifteen were exposed to formaldehyde.The tracheobronchial epithelium of all animals were examined by means of light and electron microscopy. The tracheobronchial epithelium of the control animals was found to consist of ciliated, goblet, basal and intermediate cells. The general structure of the epithelium is suggested to provide a barrier restricting the transfer of exogenous material from the airway lumen to the blood stream. Moreover, the actively motile cilia of the ciliated cells are responsible for transport of mucus with included foreign materials to the throat where the mucus normally swallowed. The goblet cells continuously secrete mucus which formed a physical barrier between the inhaled pollutants and underlying epithelium. The results of this work suggested that, both motile cilia and secretion of correct amount of mucus with suitable vesicoelasticity are responsible for maintenance of mucociliary clearance. Also the intermediate cells were observed to be differentiated into goblet cells. Following formaldehyde exposure, profound general and special epithelial and submucosal changes, ranging from moderate to severe were observed within the tracheobronchial epithelium. Early after short periods of formaldehyde exposure, the structural changes in the bronchial epithelium were observed to be less severe than that of the tracheal epithelium. However, later on, with prolongation of the period of formaldehyde exposure, both trachea and bronchi were severely affected. The general epithelial changes included, 1] ulceration of the tracheobronchial epithelium which is emphasized to expose and sensitize the airway receptors to inhaled irritants which are responsible for the pathogenesis of occupational asthma. 2] proliferative changes in the form of simple hyperplasia, basal and goblet cell hyperplasia and squamous metaplasia have occurred and suggested the possibility of formaldehyde carcinogenicity 3] thickening of the basement membrane which is considered to be a protective mechanism against inhaled formaldehyde. On the other hand, the special epithelial changes were evidenced by the appearance of a great number of ciliary abnormalities and apocrine massive mucus secretion of the goblet cells with subsequent impairment of the mucociliary clearance. Both fibrosis and airway obstruction are considered to be the latest sequlae of long term injury produced by formaldehyde exposure as indicated by the appearance of fibroblasts and smooth muscle fibers within the submucosa of tracheobronchial epithelium

The role of the collagenous and elastic system fibers in modulating bronchoconstriction

The distribution and conformational changes of the fibers of the collagenous and elastic systems in guinea pig airways after a contractile agonist challenge are described. We observed a distinct pattern of behavior within the mucosal fibers during bronchoconstriction. Part of the fibers of the two systems tend to follow the epithelial invaginations towards the airway lumen, while the remaining ones seem to be attached to the internal smooth muscle. These layers of fibers in the mucosa are interconnected to one another and to the adventitial network by slender fibers. We suggest that the configuration and behavior of these fibers during bronchoconstriction may contribute to airway reopening after the contractile stimulus has ceased. The possible role of this mechanism in the pathophysiology of human asthma is discussed.

Aparelho mucociliar: aspectos funcionais e métodos de estudo / Mucocilliary apparatus: functional aspects and methods of study

O presente estudo visa apresentar os aspectos básicos da composiçäo celular das vias aéreas, com ênfase especial aos mecanismos de retençäo de partículas e transporte mucociliar