Publications

An early granulomatous response, characterized by collections of white blood cells at foci surrounding pathogens, occurs after infection by many intracellular organisms, including Listeria, but how these clusters become organized and for what purpose remain poorly understood. Here, we showed that dendritic cell (DC) activation by Listeria nucleated rapid clustering of innate cells, including granulocytes, natural killer (NK) cells, and monocytes, to sites of bacteria propagation where interleukin-12 was expressed in the spleen. Clustered NK cells expressed interferon-gamma (IFN-gamma), which was necessary for the activation and maturation of colocalized monocytes to tumor necrosis factor- and inducible nitric oxide synthase-producing DCs (TipDCs). NK cell clustering was necessary for IFN-gamma production and required pertussis-toxin-sensitive recruitment, in part mediated by the chemokine receptor CCR5, and MyD88 adaptor-mediated signaling. Thus, spatial organization of the immune response by DCs between 6 and 24 hr ensures functional activation of innate cells, which restricts pathogens before adaptive immunity is fully activated.

The occupational contribution to chronic obstructive pulmonary disease (COPD) has yet to be put in a global perspective. In the present study, an ecological approach to this question was used, analysing group-level data from 90 sex-specific strata from 45 sites of the Burden of Obstructive Lung Disease study, the Latin American Project for the Investigation of Obstructive Lung Disease and the European Community Respiratory Health Survey follow-up. These data were used to study the association between occupational exposures and COPD Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage II or above. Regression analysis of the sex-specific group-level prevalence rates of COPD at each site against the prevalence of occupational exposure and ever-smoking was performed, taking into account mean smoking pack-yrs and mean age by site, sex, study cohort and sample size. For the entire data set, the prevalence of exposures predicted COPD prevalence (0.8% increase in COPD prevalence per 10% increase in exposure prevalence). By comparison, for every 10% increase in the proportion of the ever-smoking population, the prevalence of COPD GOLD stage II or above increased by 1.3%. Given the observed median population COPD prevalence of 3.4%, the model predicted that a 20% relative reduction in the disease burden (i.e. to a COPD prevalence of 2.7%) could be achieved by a 5.4% reduction in overall smoking rates or an 8.8% reduction in the prevalence of occupational exposures. When the data set was analysed by sex-specific site data, among males, the occupational effect was a 0.8% COPD prevalence increase per 10% change in exposure prevalence; among females, a 1.0% increase in COPD per 10% change in exposure prevalence was observed. Within the limitations of an ecological analysis, these findings support a worldwide association between dusty trades and chronic obstructive pulmonary disease for both females and males, placing this within the context of the dominant role of cigarette smoking in chronic obstructive pulmonary disease causation.

Epidermal permeability barrier formation depends upon lamellar body (LB) secretion/fusion with the apical plasma membrane (APM) of outermost stratum granulosum (SG) cell, creating cholesterol/glycosphingolipid-enriched lipid rafts-like domains. We found that the dimensions of these domains are comparable to lipid raft in other cell types; and that acute barrier disruption regulates their size and dynamics. To assess the function of these LB-derived raft-like domains, we assessed APM dynamics and barrier recovery in methyl-beta-cyclodextrin (MbetaCD)-treated hairless mice and caveolin-1 knockouts (cav-1(-/-)). MbetaCD treatment impaired APM raft-like domain formation and barrier recovery. Accelerated barrier recovery is observed in cav-1(-/-) in parallel with expansion of raft-like domains. Barrier abrogation of normal epidermis resulted in translocation of cav-1 from the cytoplasm to raft-like membrane domains, restricting further raft-like domain formation and initiating terminal differentiation. Inhibition of LB secretion by monensin and absence of cav-1 delayed terminal differentiation. Furthermore, cav-1(-/-) mice exhibited an increased propensity to develop experimentally induced epidermal hyperplasia correlating with lipid raft persistence. Finally, the epidermal hyperplasia in psoriasis and Netherton syndrome is paralleled by increased lipid raft formation. These studies demonstrate that cav-1 delivery to the APM by LB trafficking to APM "brakes" further LB secretion, signals terminal differentiation, and regulates epidermal hyperproliferation.

CONTEXT

Several practice guidelines recommend that depression be evaluated and treated in patients with cardiovascular disease, but the potential benefits of this are unclear.

OBJECTIVE

To evaluate the potential benefits of depression screening in patients with cardiovascular disease by assessing (1) the accuracy of depression screening instruments; (2) the effect of depression treatment on depression and cardiac outcomes; and (3) the effect of screening on depression and cardiac outcomes in patients in cardiovascular care settings.

DATA SOURCES

MEDLINE, PsycINFO, CINAHL, EMBASE, ISI, SCOPUS, and Cochrane databases from inception to May 1, 2008; manual journal searches; reference list reviews; and citation tracking of included articles.

STUDY SELECTION

We included articles in any language about patients in cardiovascular care settings that (1) compared a screening instrument to a valid major depressive disorder criterion standard; (2) compared depression treatment with placebo or usual care in a randomized controlled trial; or (3) assessed the effect of screening on depression identification and treatment rates, depression, or cardiac outcomes.

DATA EXTRACTION

Methodological characteristics and outcomes were extracted by 2 investigators.

RESULTS

We identified 11 studies about screening accuracy, 6 depression treatment trials, but no studies that evaluated the effects of screening on depression or cardiovascular outcomes. In studies that tested depression screening instruments using a priori-defined cutoff scores, sensitivity ranged from 39% to 100% (median, 84%) and specificity ranged from 58% to 94% (median, 79%). Depression treatment with medication or cognitive behavioral therapy resulted in modest reductions in depressive symptoms (effect size, 0.20-0.38; r(2), 1%-4%). There was no evidence that depression treatment improved cardiac outcomes. Among patients with depression and history of myocardial infarction in the ENRICHD trial, there was no difference in event-free survival between participants treated with cognitive behavioral therapy supplemented by an antidepressant vs usual care (75.5% vs 74.7%, respectively).

CONCLUSIONS

Depression treatment with medication or cognitive behavioral therapy in patients with cardiovascular disease is associated with modest improvement in depressive symptoms but no improvement in cardiac outcomes. No clinical trials have assessed whether screening for depression improves depressive symptoms or cardiac outcomes in patients with cardiovascular disease.