Novel Therapy of Bicarbonate, Glutathione, and Ascorbic Acid Improves Cystic Fibrosis Mucus Transport.

Defective airway mucus clearance is a defining characteristic of cystic fibrosis lung disease, and improvements to current mucolytic strategies are needed. Novel approaches targeting a range of contributing mechanisms are in various stages of preclinical and clinical development. ARINA-1 is a new nebulized product comprised of ascorbic acid, glutathione, and bicarbonate. Using microoptical coherence tomography, we tested the effect of ARINA-1 on central features of mucociliary clearance in F508del/F508del primary human bronchial epithelial cells to assess its potential as a mucoactive therapy in cystic fibrosis. We found that ARINA-1 significantly augmented mucociliary transport rates, both alone and with CFTR (cystic fibrosis transmembrane conductance regulator) modulator therapy, whereas airway hydration and ciliary beating were largely unchanged compared with PBS vehicle control. Analysis of mucus reflectivity and particle-tracking microrheology indicated that ARINA-1 restores mucus clearance by principally reducing mucus layer viscosity. The combination of bicarbonate and glutathione elicited increases in mucociliary transport rate comparable to those seen with ARINA-1, indicating the importance of this interaction to the impact of ARINA-1 on mucus transport; this effect was not recapitulated with bicarbonate alone or bicarbonate combined with ascorbic acid. Assessment of CFTR chloride transport revealed an increase in CFTR-mediated chloride secretion in response to ARINA-1 in CFBE41o- cells expressing wild-type CFTR, driven by CFTR activity stimulation by ascorbate. This response was absent in CFBE41o- F508del cells treated with VX-809 and primary human bronchial epithelial cells, implicating CFTR-independent mechanisms for the effect of ARINA-1 on cystic fibrosis mucus. Together, these studies indicate that ARINA-1 is a novel potential therapy for the treatment of impaired mucus clearance in cystic fibrosis.

Macrolide use leads to clinical and radiological improvement in patients with cryptogenic organizing pneumonia.

Cryptogenic organizing pneumonia is an idiopathic form of organizing pneumonia (also known as bronchiolitis obliterans organizing pneumonia). Because cryptogenic organizing pneumonia is considered an inflammatory disease, it characteristically responds to the broad-spectrum antiinflammatory corticosteroids, although relapse is common on discontinued use. Additionally, long-term use of corticosteroids has many side effects. In severe cases in which corticosteroids have failed, either cytotoxic therapy or macrolide therapy is used. Because of the toxicity and adverse effects of cytotoxic therapy (e.g., cyclophosphamide), this therapy option cannot be used long term in refractory cases. Macrolide therapy has been shown to be an effective antiinflammatory agent that is relatively safe when used on a long-term basis in patients with cryptogenic organizing pneumonia.

Use of the cockroach antigen model of acute asthma to determine the immunomodulatory role of early exposure to gastrointestinal infection.

The increased incidence of asthma over the last 50 years in developed countries has been associated with a decrease in infections acquired early in childhood. These early infections are thought to shape subsequent immune responses. Although there have been multiple clinical associations between gastrointestinal infections and decreased asthma incidence, it has been difficult to move beyond a simple correlation when studying human patients. This section describes an acute asthma model in C57BL/6 mice designed to specifically evaluate the effect of prior gastric Helicobacter colonization and inflammation in a murine model of cockroach allergen-induced asthma.

Outcome of nicotine replacement therapy in patients admitted to ICU: a randomized controlled double-blind prospective pilot study.

BACKGROUND: The effect of nicotine withdrawal in smokers admitted to the ICU is not well understood, so the role of nicotine replacement therapy (NRT) in those patients is controversial. OBJECTIVE: To determine whether NRT in ICU patients affects the need for sedatives/analgesics, ventilator days, and ICU stay. METHODS: In a 20-bed ICU, 40 subjects were randomized to either a 21 mg nicotine patch or a placebo nicotine patch daily until either ICU discharge, transfer to a medical floor, or 10 weeks in the ICU. We collected data on sedatives/analgesics use during ICU stay and use and duration of mechanical ventilation . RESULTS: There were 27 male and 13 female subjects. The mean age was 57.4 y in the intervention group and 52.5 y in the control group. The mean Acute Physiology and Chronic Health Evaluation II score was 14.3 in the intervention group and 13.8 in the control group. The mean ICU stay was 4.5 d in the intervention group and 7 d in the control group. The mean number of days on ventilator was 1.9 in the intervention group and 3.5 in the control group. The number of days on sedation/analgesia was less in the intervention group than in the control group. CONCLUSIONS: Although ICU stay and ventilator days decreased numerically in this pilot study, statistically there was no beneficial effect from NRT. (International Standard Randomised Controlled Trial Register ISRCTN66928309).

Helicobacter felis--associated gastric disease in microbiota-restricted mice.

Human Helicobacter pylori infection leads to multiple pathological consequences, including gastritis and adenocarcinoma. Although this association has led to the classification of H. pylori as a type 1 carcinogen, it is not clear if additional nonhelicobacter gastric microbiota play a role in these diseases. In this study, we utilized either specific pathogen-free C57BL/6 mice (B6.SPF) or mice colonized with altered Schaedler flora (B6.ASF) to evaluate the role of nonhelicobacter gastric microbiota in disease development after Helicobacter felis infection. Despite similar histological changes, H. felis persisted in B6.ASF stomachs, while H. felis could no longer be detected in the majority of B6.SPF mice. The B6.SPF mice also acquired multiple Lactobacillus spp. in their stomachs after H. felis infection. Our data indicate that potential mechanisms responsible for the ineffective H. felis clearance in the B6.ASF model include the absence of new gastric microbiota to compete for the gastric niche, the lack of expression of new gastric mucins, and a reduced ratio of H. felis-specific IgG2c:IgG1 serum antibodies. These data suggest that although H. felis is sufficient to initiate gastric inflammation and atrophy, bacterial eradication and the systemic immune response to infection are significantly influenced by pre-existing and acquired gastric microbiota.

Gastric mucus alterations associated with murine Helicobacter infection.

The C57BL/6 mouse has been shown to develop gastric adenocarcinoma after Helicobacter felis infection. This model was used to determine whether mucin and trefoil factor (TFF) expression after infection was altered in a similar fashion to the changes seen in the protective gastric mucus layer of the human stomach after H. pylori infection. Our results indicate that this mouse model mimics many of the changes seen after human H. pylori infection, including increased expression of muc4 and muc5b and loss of muc5ac. These alterations in mucin expression occurred as early as 4 weeks postinfection, before the development of significant mucous metaplasia or gastric dysplasia. The decrease in muc5ac expression occurred only in the body of the stomach and was not secondary to the adaptive immune response to infection, because a similar decrease in expression was seen after infection of B6.Rag-1(-/-) mice, which lack B and T cells. Intriguingly, the increased expression of Muc4 and Muc5b in infected C57BL/6 mice was not seen in the infected B6.Rag-1(-/-) mice. Because B6.Rag-1(-/-) mice do not develop gastric pathology after H. felis infection, these findings point to the potential role of Muc4 and Muc5b in disease progression. This manuscript contains online supplemental material at http://www.jhc.org. Please visit this article online to view these materials.