Acute Moraxella catarrhalis Airway Infection of Chronically Smoke-Exposed Mice Increases Mechanisms of Emphysema Development: A Pilot Study

In chronic obstructive pulmonary disease (COPD), acute exacerbations and emphysema development are characteristics for disease pathology. COPD is complicated by infectious exacerbations with acute worsening of respiratory symptoms with Moraxella catarrhalis as one of the most frequent pathogens. Although cigarette smoke (CS) is the primary risk factor, additional molecular mechanisms for emphysema development induced by bacterial infections are incompletely understood. We investigated the impact of M. catarrhalis on emphysema development in CS exposed mice and asked whether an additional infection would induce a solubilization of pro-apoptotic and pro-inflammatory endothelial monocyte-activating-protein-2 (EMAPII) to exert its activities in the pulmonary microvas-culature and other parts of the lungs not exposed directly to CS.

Mice were exposed to smoke (6 or 9 months) and/or infected with M. catarrhalis. Lungs, bronchoalveolar lavage fluid (BALF), and plasma were analyzed.

CS exposure reduced ciliated area, caused rarefaction of the lungs, and induced apoptosis. EMAPII was increased independent of prior smoke exposure in BALF of infected mice. Importantly, acute M. catarrhalis infection increased release of matrixmetalloproteases-9 and -12, which are involved in emphysema development and comprise a mechanism of EMAPII release.

Our data suggest that acute M. catarrhalis infection represents an independent risk factor for emphysema development in smoke-exposed mice.

Older adult psychiatric inpatients with non-cognitive disorders should be screened for vitamin B12 deficiency

OBJECTIVE

Vitamin B12 (B12) deficiency is most prevalent among older adults. Practice guidelines recommend screening older adults with symptoms of cognitive disorder for B12 deficiency. However, guidelines for non-cognitive psychiatric disorders typically do not mention screening older adults for B12 deficiency. The purpose of this study was to determine whether routine screening of older adult psychiatric inpatients for B12 deficiency, regardless of cognitive symptoms, is clinically justified.

DESIGN

We conducted a retrospective chart-review study of consecutive inpatient admissions.

SETTING

Older Adult Acute Psychiatric Inpatient Unit at the University of Maryland Medical Center from 10/2007-4/2010.

PARTICIPANTS

Acute psychiatric inpatients aged ≥50 years who met inclusion criteria (N=374).

MEASUREMENTS

Mean (SD) B12 levels and percentages of probable (<180pg/mL) and possible (180-350pg/mL) B12 deficiency as well as characteristics of patients with probable and possible B12 deficiency compared to patients with optimal B12 levels.

RESULTS

Mean (SD) B12 levels and percentages of probable and possible B12 deficiency, respectively, for cognitive disorder patients [468 (284) pg/mL, 7.8 % (n=5) and 29.7% (n=19)] and for non-cognitive disorder patients [481(268) pg/mL, 4.8 %(n=15) and 33.2%( n=103)] were not significantly different (t=0.339, df=372, P=0.735; χ2=1.084, df=2, P=0.582, respectively).

CONCLUSION

Considering the potential benefits and low costs of screening and treatment, we conclude that it is justified to routinely screen older adult psychiatric inpatients for B12 deficiency whether or not cognitive disorder symptoms are present.