Management of severe tracheal anomalies remains a clinical challenge. Tissue engineering offers new hope in trachea reconstruction surgery. However to date no optimal technique achieved in the formation of human or animal trachea. The main problem lies on the biomaterial used and the complex city of forming trachea in vivo. This study was aimed at creating tissue-engineered trachea cartilage from easily accessible human and animal nasal septum cartilage using internal scaffold and biodegradable human and animal fibrin.
The effects of a mixed infection of Mycoplasma gallinarum and Newcastle disease virus (F strain) on the tracheal epithelium of village chickens were investigated and observed by scanning electron microscopy. Day-old village chicks were vaccinated intranasally with F strain Newcastle disease virus and inoculated intratracheally on the same day with 10(8) colony forming units of M gallinarum. In another study the chicks were vaccinated and then infected with M gallinarum seven days later. The first group of chicks was euthanased three, seven, 10, 14 and 21 days after vaccination and infection and the vaccinated chicks were euthanased three, seven, 10 and 14 days after infection. In the chicks vaccinated and infected on the same day, major alterations to the tracheal epithelium were visible three days later. There were fewer ciliated cells and the borders of the non-ciliated cells were prominent. Several depressions had formed in the epithelial surface. At higher magnification, clumps of microvilli were visible on some of the non-ciliated cells. Seven days after vaccination and infection, the tracheal epithelium appeared normal, with an increase in the numbers of ciliated cells, although raised borders were observed on the non-ciliated cells in some areas. No clumping of microvilli or depressions in the epithelial surface were observed. In the chicks infected seven days after vaccination, the tracheal epithelium appeared normal with no visible changes on its surface.
Airway stem/progenitor epithelial cells (AECs) are notable for their differentiation capacities in response to lung injury. Our previous finding highlighted the regenerative capacity of AECs following transplantation in repairing tracheal injury and reducing the severity of alveolar damage associated acute lung injury in a rabbit model. The goal of this study is to further investigate the potential of AECs to re-populate the tracheal epithelium and to study their stimulatory effect on inhibiting pro-inflammatory cytokines, epithelial cell migration and proliferation, and epithelial-to-mesenchymal transition (EMT) process following tracheal injury. Two in vitro culture assays were applied in this study; the direct co-culture assay that involved a culture of decellularised tracheal epithelium explants and AECs in a rotating tube, and indirect co-culture assay that utilized microporous membrane-well chamber system to separate the partially decellularised tracheal epithelium explants and AEC culture. The co-culture assays provided evidence of the stimulatory behaviour of AECs to enhance tracheal epithelial cell proliferation and migration during early wound repair. Factors that were secreted by AECs also markedly suppressed the production of IL-1β and IL-6 and initiated the EMT process during tracheal remodelling.
PURPOSE: The aim of this study was to evaluate the narrowing of the trachea in head and neck surgical patients who had undergone elective tracheostomy.
MATERIALS AND METHODS: This is a prospective study. Twenty-five patients were included in this study. All these patients had a preoperative elective tracheotomy, preceding major head and neck surgery for head and neck malignancies. An x-ray of the lateral soft tissue neck was taken after a minimum of 6 weeks after the dissimulation of tracheotomy tube. Diameter of the trachea above the stoma (around 2 cm below the cricoid ring that can be clearly seen in lateral x-ray corresponding to the second tracheal ring) was taken as controls. Data were entered into a computer database and statistically analyzed using SPSS for Windows (version 12.0; SPSS, Chicago, Ill). In addition to descriptive statistics for all patients, inferential statistics were used to compare the 2 tracheal diameters across all patients and within the subgroups of men and women. Associations between outcome and other variables were evaluated statistically using an chi 2 test for the categorical data. Other parametric and nonparametric statistical tests were used when appropriate. Criterion for statistical significance was set at P < .05 (Student t test and 2-tailed test).
RESULTS: From this study, 92% (23/25) patients developed narrowing of trachea, all less than 50%. Very early decanulation of tracheotomy shows low or no narrowing at all. There is gradual narrowing in patients in whom dissimulations were performed after 14 days. Ethnicities of Indian decent (13/25) predominate in this study population. Male patients in this study have shorter decanulation period compared with female.
CONCLUSIONS: Elective surgical tracheotomy is a relatively safe procedure resulting in minimum asymptomatic tracheal stenosis.
Study site: University Malaya Medical Centre, Kuala Lumpur, Malaysia
Aerosol-based cell therapy has emerged as a novel and promising therapeutic strategy for treating lung diseases. The goal of this study was to determine the safety and efficacy of aerosol-based airway epithelial cell (AEC) delivery in the setting of acute lung injury induced by tracheal brushing in rabbit. Twenty-four hours following injury, exogenous rabbit AECs were labelled with bromodeoxyuridine and aerosolized using the MicroSprayer® Aerosolizer into the injured airway. Histopathological assessments of the injury in the trachea and lungs were quantitatively scored (1 and 5 days after cell delivery). The aerosol-based AEC delivery appeared to be a safe procedure, as cellular rejection and complications in the liver and spleen were not detected. Airway injury initiated by tracheal brushing resulted in disruption of the tracheal epithelium as well as morphological damage in the lungs that is consistent with acute lung injury. Lung injury scores were reduced following 5 days after AEC delivery (AEC-treated, 0.25 ± 0.06 vs. untreated, 0.53 ± 0.05, P trachea, AEC delivery led to an upsurge in epithelium regeneration and repair. Re-epithelialization was significantly increased 5 days after treatment (AEC-treated, 91.07 ± 2.37% vs. untreated, 62.99 ± 7.39%, P
Twenty-four 8 to 9 week-old Pasteurella multocida -free rabbits were divided into three equal groups, the first group was pretreated with hydrocortisone and inoculated intranasally with pasteurella multocida serotype A:3. The second group was inoculated intranasally with P. multocida without hydrocortisone treatment. The third group was inoculated with phosphate buffered saline only and used as a control group. Pasteurella multocida was isolated from the nasal cavity of all infected rabbits in group 1 and 2 and from the trachea of seven rabbits in group 1 and five rabbits in group 2. This study was conducted to observe the ultrastructural changes of the upper respiratory tract of hydrocortisone treated and non-treated rabbits infected with P. multocida serotype A:3. The ultrastructural changes detected in infected rabbits were ciliary destruction and deciliation of the ciliated epithelial cells, cellular swelling, goblet cell hyperplasia and endothelial cell damage. Pasteurella multocida was observed attached to the degenerated cilia, microvilli and mucus. Pasteurella multocida infection was associated with inflammatory responses, which may have caused tissue damage. It is possible that hydrocortisone modulates the severity of infection as an immune suppressor and an inhibitor of goblet cell secretion.
Pulmonary atelectasis may be caused by endobronchial lesions or by extrinsic compression of the bronchus. However, lung collapse due to compression from a thoracic aneurysm is uncommon. We report a 76-year-old hypertensive female patient who has pulmonary atelectasis due to an extrinsic compression from a descending thoracic aortic aneurysm, and discuss possible treatment options.
The in vivo action of the antimicrobial peptide melittin, expressed from a recombinant plasmid vector, on chickens experimentally infected with Mycoplasma gallisepticum was studied. The plasmid vector pBI/mel2/rtTA includes the melittin gene under the control of an inducible tetracycline-dependent human cytomegalovirus promoter and the gene coding for the trans-activation protein rtTA. Aerosol administration of the vector, followed by infecting the chickens with M. gallisepticum 1226, is shown to inhibit development of infection. The inhibitory action was confirmed by a complex of clinical, pathomorphological, histological and serological studies, and also by comparing the M. gallisepticum reisolation frequency from the respiratory tract and internal organs. The data suggest that plasmid vectors expressing genes of antimicrobial peptides can be considered as potential agents for the prevention and treatment of mycoplasma infections in poultry farming.
A human isolate of Nipah virus from an outbreak of febrile encephalitis in Malaysia that coincided with a field outbreak of disease in pigs was used to infect eight 6-week-old pigs orally or subcutaneously and two cats oronasally. In pigs, the virus induced a respiratory and neurological syndrome consistent with that observed in the Malaysian pigs. Not all the pigs showed clinical signs, but Nipah virus was recovered from the nose and oropharynx of both clinically and sub-clinically infected animals. Natural infection of in-contact pigs, which was readily demonstrated, appeared to be acute and self-limiting. Subclinical infections occurred in both inoculated and in-contact pigs. Respiratory and neurological disease was also produced in the cats, with recovery of virus from urine as well as from the oropharynx. The clinical and pathological syndrome induced by Nipah virus in cats was comparable with that associated with Hendra virus infection in this species, except that in fatal infection with Nipah virus there was extensive inflammation of the respiratory epithelium, associated with the presence of viral antigen. Viral shedding via the nasopharynx, as observed in pigs and cats in the present study, was not a regular feature of earlier reports of experimental Hendra virus infection in cats and horses. The findings indicate the possibility of field transmission of Nipah virus between pigs via respiratory and oropharyngeal secretions.
Sixteen 8- to 9-week-old Pasteurella multocida-free New Zealand White rabbits were divided into two equal groups. The first group was inoculated intranasally with P multocida serotype D:1 strain and the second group that was inoculated with phosphate-buffered saline (PBS) only was used as a control group. Pasteurella multocida was isolated from the nasal cavity of all infected rabbits in group 1 and from tracheal swabs of seven rabbits in this group. Four rabbits in group 1 died with clinical signs of septicaemia, two rabbits had mucopurulent nasal discharge and pneumonic lesions and the other two did not show any clinical signs or gross lesions. The ultrastructural changes detected were deciliation or clumping of cilia of ciliated epithelium, cellular swelling, vacuolation and sloughing. The subepithelial capillaries showed congestion, intravascular fibrin deposition, platelets aggregation and endothelial injury. Pasteurella multocida was observed attached to the injured endothelial cells. Heterophils, mast cells, vacuolated monocytes and macrophages infiltrated the lamina propria and between the degenerated epithelial cells.