Risky behavior in teens with cystic fibrosis or sickle cell disease: a multicenter study.

Objective: To determine the prevalence and age of onset of common risky behaviors such as smoking and sexual activity in teens with cystic fibrosis and those with sickle cell disease and to compare their behaviors with those of adolescents in the general population.

Design: Survey.

Setting: All five major pediatric tertiary care centers in North Carolina (study participants with sickle cell disease or cystic fibrosis) and North Carolina public schools (comparison population).

Mediastinal lymphadenopathy caused by Mycobacterium avium-intracellulare complex in a child with normal immunity: successful treatment with anti-mycobacterial drugs and laser bronchoscopy.

We report on the case of a 9-month-old Caucasian girl referred to our institution with a history of fever of unknown origin and wheezing, unresponsive to bronchodilator and anti-inflammatory therapy. Subsequent investigation led to a diagnosis of mediastinal lymphadenopathy caused by Mycobacterium avium-intracellulare (MAI). The infected lymph tissue infiltrated and obstructed the right bronchus and significantly compressed the left bronchus to the point of near closure.

Nasal and bronchoalveolar lavage fluid cytokines in early cystic fibrosis.

Cytokine levels in nasal and lower airways in young cystic fibrosis (CF) patients were compared with those in controls. Nasal (NLF) and bronchoalveolar (BALF) lavage fluids were obtained from children with or without CF who were undergoing bronchoscopy for clinical indications. In NLF, neither inflammatory cells nor cytokine concentrations differed between patients and controls.

Cytokine production by cultured human bronchial epithelial cells infected with a replication-deficient adenoviral gene transfer vector or wild-type adenovirus type 5.

Exposure of animals to adenoviral gene transfer vectors has been associated with respiratory tract inflammation. The pathogenesis of this inflammation is unclear. One hypothesis is that viral vectors directly induce production of inflammatory cytokines by host cells in the airways.

A controlled study of adenoviral-vector-mediated gene transfer in the nasal epithelium of patients with cystic fibrosis.

Background: Cystic fibrosis is a monogenic disease that deranges multiple systems of ion transport in the airways, culminating in chronic infection and destruction of the lung. The introduction of a normal copy of the cystic fibrosis transmembrane conductance regulator (CFTR) gene into the airway epithelium through gene transfer is an attractive approach to correcting the underlying defects in patients with cystic fibrosis. We tested the feasibility of gene therapy using adenoviral vectors in the nasal epithelium of such patients.

Effect of adenoviral vector infection on cell proliferation in cultured primary human airway epithelial cells.

Although recombinant adenoviruses are used as vectors for delivering therapeutic genes to the airways of cystic fibrosis (CF) patients, the effects of these vectors on the kinetics of airway epithelial cell growth have not been investigated. We tested whether E1, E3-deleted Ad vectors (Ad5-CMV-lacZ) affect the kinetics of cell proliferation of human airway epithelial cells in primary culture. There was a dose-dependent relationship between the vector multiplicity of infection (moi) and the efficiency of Ad-mediated lacZ gene transfer.

Cell proliferation in bronchial epithelium and submucosal glands of cystic fibrosis patients.

Integrative gene therapy typically requires dividing cells. This requirement has been perceived as an impediment for gene transfer to mature, uninjured airways where proliferation rates are very low. In diseases such as cystic fibrosis (CF) that may be candidates for integrative gene therapy, airway cell turnover is not known but may be increased as a result of chronic inflammation.

Receptor specificity of influenza virus influences severity of illness in ferrets.

Weanling ferrets were inoculated intranasally with either wild-type or receptor-variant clones of influenza A/Memphis/102/72 to determine if changes in receptor specificity influence virulence of influenza virus infection. Over the 5 days after inoculation, receptor-variant inoculated ferrets had a lower mean elevation in body temperature, greater weight gain and less sneezing than the wild-type group. Influenza virus was recovered from the lungs of fewer receptor-variant infected ferrets (5/12 vs 11/12) and in lower titers than in wild-type infected ferrets at 5 days after inoculation.

Increased adherence of Staphylococcus aureus from cystic fibrosis lungs to airway epithelial cells.

Airway colonization by Staphylococcus aureus is a frequent feature of cystic fibrosis (CF). To assess the pathogenesis of selective colonization with this organism, we compared the capacity of S. aureus isolated from the respiratory tract of CF and non-CF patients to adhere to epithelial cells from the upper and lower airways of CF and control subjects.

Development of mucociliary transport in the postnatal ferret trachea.

Little is known of the developmental aspects of mucociliary transport. Previous studies have documented that newborn ferret trachea has very few ciliated cells but numerous immature secretory cells in the epithelium and only rudimentary submucosal glands. Rapid and complete maturation occurs in the first postnatal month.

Mycoplasma pneumoniae as the causative agent for pneumonia in the immunocompromised host.

A young man undergoing chemotherapy for Ewing's sarcoma presented with fever, neutropenia, anemia, thrombocytopenia, and a new infiltrate on the chest roentgenogram. Routine cultures and cytopathologic examination of bronchoalveolar lavage fluid provided no evidence for an etiology; however, special cultures of the BAL fluid demonstrated heavy growth of Mycoplasma pneumoniae. We recommend that evaluation of pneumonia in the immuno-compromised host include appropriate cultures of BAL fluid for M pneumoniae, particularly when the patient is 5 to 25 years old, the age of high incidence of mycoplasmal pneumonia.

Pathogenesis of respiratory infections due to influenza virus: implications for developing countries.

The influenza viruses have an important and distinctive place among respiratory viruses: they change antigenic character at irregular intervals, infect individuals of all ages, cause illnesses characterized by constitutional symptoms and tracheobronchitis, produce yearly epidemics associated frequently with excess morbidity and mortality, and predispose the host to bacterial superinfections. Much is known about influenza viruses, but their role in respiratory infections among children in developing countries is poorly understood, and the risk factors that lead to the excess morbidity and mortality have not been identified clearly. Among the many risk factors that may be important are alterations in host immunity, malnutrition, prior or coincident infections with other microorganisms, inhaled pollutants, and lack of access to medical care.

Attachment of influenza A virus to ferret tracheal epithelium at different maturational stages.

Influenza virus attaches primarily to ciliated cells in mature airways epithelium. This process is mediated by a viral envelope glycoprotein (hemagglutinin) that binds to sialic acid-containing receptors in the apical membrane of host cells. The purpose of this study was to determine the cellular distribution of these receptors as a function of tracheal epithelial maturation in the ferret, which is susceptible to influenza virus infection at all ages and undergoes postnatal ciliation.

Developmental changes of ferret tracheal mucin composition and biosynthesis.

We characterized the chemical composition of mucins secreted by ferret tracheal explants and the activities of key mucin glycosyltransferases in ferret tracheal epithelium during a period of rapid postnatal maturation of the mucin-secreting structures. Ferret tracheal explants secrete three major groups of high molecular weight glycoconjugates: (1) those susceptible to bovine testicular hyaluronidase; (2) those resistant to hyaluronidase and exhibiting high density (p greater than or equal to 1.60 g/mL); and (3) those resistant to hyaluronidase and exhibiting low density (1.

Development, organization, and function of tight junctional complexes in the tracheal epithelium of infant ferrets.

The surface epithelium of newborn ferret airways matures rapidly in the first month of life. Prominent developmental features include a transition from predominantly non-ciliated to ciliated cells, quantitative and qualitative changes in secretion of macromolecules, and a transition from secretory to absorptive patterns of ion transport. Freeze-fracture replicas of ferret tracheal epithelium from 0 to 28 days of age exhibited progressive developmental patterns in tight junctional structure from beaded, unclosed patterns in newborns to more closed patterns at 28 days.

Chlamydial and mycoplasmal pneumonias.

Chlamydia species and Mycoplasma pneumoniae are among the most common agents of community-acquired pneumonia, as well as causes of various nonpneumonic syndromes. Both can be considered "exotic" bacteria: Chlamydiae because they depend on host cell energy, hence their obligate intracellular replication; and M pneumoniae because it is an extracellular parasite that lacks the standard protective bacterial cell wall. The unusual biology of these organisms complicates laboratory diagnosis, but because both are susceptible to selective antimicrobials, therapy often proceeds empirically on clinical suspicion.