Publications

Osteoporosis and osteoporosis-related fractures are growing problems with the aging population and are associated with significant morbidity and mortality. At this time, other than parathyroid hormone analogs, all therapies for osteoporosis are antiresorptive. Therefore, researchers have focused efforts on development of more anabolic therapies. Understanding of the Wnt signaling pathway, which is critical for skeletal development, and the role of sclerostin in inhibition of Wnt signaling has led to the discovery of a novel therapeutic approach in the treatment of osteoporosis - sclerostin inhibition. In this review, we discuss the biology of Wnt signaling and sclerostin inhibition. We then discuss human disorders of decreased sclerostin function and animal models of sclerostin inhibition. Both have served to elucidate the effects of decreased sclerostin levels and function - increased bone mass and strength and fewer fractures. In addition, we review data from Phase I and II studies of the two humanized sclerostin monoclonal antibodies, romosozumab and blosozumab, both of which have had positive effects on bone mineral density. We conclude with a discussion of the ongoing Phase III studies of romosozumab. The available data support the potential for neutralizing sclerostin monoclonal antibodies to serve as anabolic agents in the treatment of osteoporosis.

BACKGROUND

Inhalation of ambient levels of ozone causes airway inflammation and epithelial injury.

METHODS

To examine the responses of airway cells to ozone-induced oxidative injury, 19 subjects (7 with asthma) were exposed to clean air (0ppb), medium (100ppb), and high (200ppb) ambient levels of ozone for 4h on three separate occasions in a climate-controlled chamber followed by bronchoscopy with bronchoalveolar lavage (BAL) 24h later. BAL cell mRNA expression was examined using Affymetrix GeneChip Microarray. The role of a differentially expressed gene (DEG) in epithelial injury was evaluated in an in vitro model of injury [16HBE14o- cell line scratch assay].

RESULTS

Ozone exposure caused a dose-dependent up-regulation of several biologic pathways involved in inflammation and repair including chemokine and cytokine secretion, activity, and receptor binding; metalloproteinase and endopeptidase activity; adhesion, locomotion, and migration; and cell growth and tumorigenesis regulation. Asthmatic subjects had 1.7- to 3.8-fold higher expression of many DEGs suggestive of increased proinflammatory and matrix degradation and remodeling signals. The most highly up-regulated gene was osteopontin, the protein level of which in BAL fluid increased in a dose-dependent manner after ozone exposure. Asthmatic subjects had a disproportionate increase in non-polymerized osteopontin with increasing exposure to ozone. Treatment with polymeric, but not monomeric, osteopontin enhanced the migration of epithelial cells and wound closure in an α9β1 integrin-dependent manner.

CONCLUSIONS

Expression profiling of BAL cells after ozone exposure reveals potential regulatory genes and pathways activated by oxidative stress. One DEG, osteopontin, promotes epithelial wound healing in an in vitro model of injury.

BACKGROUND

Return visits to the emergency department (ED) or hospital after an index ED visit strain the health system, but information about rates and determinants of revisits is limited.

OBJECTIVE

To describe revisit rates, variation in revisit rates by diagnosis and state, and associated costs.

DESIGN

Observational study using the Healthcare Cost and Utilization Project databases.

SETTING

6 U.S. states.

PATIENTS

Adults with ED visits between 2006 and 2010.

MEASUREMENTS

Revisit rates and costs.

RESULTS

Within 3 days of an index ED visit, 8.2% of patients had a revisit; 32% of those revisits occurred at a different institution. Revisit rates varied by diagnosis, with skin infections having the highest rate (23.1% [95% CI, 22.3% to 23.9%]). Revisit rates also varied by state. For skin infections, Florida had higher risk-adjusted revisit rates (24.8% [CI, 23.5% to 26.2%]) than Nebraska (10.6% [CI, 9.2% to 12.1%]). In Florida, the only state with complete cost data, total revisit costs for the 19.8% of patients with a revisit within 30 days were 118% of total index ED visit costs for all patients (including those with and without a revisit).

LIMITATION

Whether a revisit reflects inadequate access to primary care, a planned revisit, the patient's nonadherence to ED recommendations, or poor-quality care at the initial ED visit remains unknown.

CONCLUSION

Revisits after an index ED encounter are more frequent than previously reported, in part because many occur outside the index institution. Among ED patients in Florida, more resources are spent on revisits than on index ED visits.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality.

IMPORTANCE

Intra-aortic balloon pump (IABP) therapy is a widely used intervention for acute myocardial infarction with cardiogenic shock. Guidelines, which previously strongly recommended it, have recently undergone substantial change.

OBJECTIVE

To assess IABP efficacy in acute myocardial infarction.

DATA SOURCES

Human studies found in Pubmed, Embase, and Cochrane libraries through December 2014 and in reference lists of selected articles. Search strings were "myocardial infarction" or "acute coronary syndrome" and "intra-aortic balloon pump" or "counterpulsation."

STUDY SELECTION

Randomized clinical trials (RCTs) and observational studies comparing use of IABP with no IABP in patients with acute myocardial infarction.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently extracted the data, and risk of bias in RCTs was assessed using the Cochrane risk of bias tool. We conducted separate meta-analyses of the RCTs and observational studies. Data were quantitatively synthesized using random-effects meta-analysis.

MAIN OUTCOMES AND MEASURES

Thirty-day mortality.

RESULTS

There were 12 eligible RCTs randomizing 2123 patients. In the RCTs, IABP use had no statistically significant effect on mortality (odds ratio [OR], 0.96 [95% CI, 0.74-1.24]), with no significant heterogeneity among trials (I2 = 0%; P = .52). This result was consistent when studies were stratified by the presence (OR, 0.94 [95% CI, 0.69-1.28]; P = .69, I2 = 0%) or absence (OR, 0.98 [95% CI, 0.57-1.69]; P = .95, I2 = 17%) of cardiogenic shock. There were 15 eligible observational studies totaling 15 530 patients. Their results were mutually conflicting (heterogeneity I2 = 97%; P < .001), causing wide uncertainty in the summary estimate for the association with mortality (OR, 0.96 [95% CI, 0.54-1.70]). A simple index of baseline risk marker imbalance in the observational studies appeared to explain much of the heterogeneity in the observational data (R2meta = 46.2%; P < .001).

CONCLUSIONS AND RELEVANCE

Use of IABP was not found to improve mortality among patients with acute myocardial infarction in the RCTs, regardless of whether patients had cardiogenic shock. The observational studies showed a variety of mutually contradictory associations between IABP therapy and mortality, much of which was explained by the differences between studies in the balance of risk factors between IABP and non-IABP groups.

The article reviews data on HIV testing, treatment, and care outcomes for women who use drugs in 5 countries across 5 continents. We chose countries in which the HIV epidemic has, either currently or historically, been fueled by injection and non-injection drug use and that have considerable variation in social structural and drug policies: Argentina, Vietnam, Australia, Ukraine, and the United States. There is a dearth of available HIV care continuum outcome data [ie, testing, linkage, retention, antiretroviral therapy (ART) provision, viral suppression] among women drug users, particularly among noninjectors. Although some progress has been made in increasing HIV testing in this population, HIV-positive women drug users in 4 of the 5 countries have not fully benefitted from ART nor are they regularly engaged in HIV care. Issues such as the criminalization of drug users, HIV-specific criminal laws, and the lack of integration between substance use treatment and HIV primary care play a major role. Strategies that effectively address the pervasive factors that prevent women drug users from engaging in HIV care and benefitting from ART and other prevention services are critical. Future success in enhancing the HIV continuum for women drug users should consider structural and contextual level barriers and promote social, economic, and legal policies that overhaul the many years of discrimination and stigmatization faced by women drug users worldwide. Such efforts must emphasis the translation of policies into practice and approaches to implementation that can help HIV-infected women who use drugs engage at all points of the HIV care continuum.