Publications

BACKGROUND

extracellular matrix (ECM) components are instrumental in maintaining homeostasis and muscle fiber functional integrity. Skeletal muscle hypertrophy is associated with ECM remodeling. Specifically, recent studies have reported the involvement of matrix metalloproteinases (MMPs) in muscle ECM remodeling. However, the functional role of MMPs in muscle hypertrophy remains largely unknown.

METHODS

in this study, we examined the role of MMP-2 in skeletal muscle hypertrophy using a previously validated method where the plantaris muscle of mice were subjected to mechanical overload due to the surgical removal of synergist muscles (gastrocnemius and soleus).

RESULTS

following two weeks of overload, we observed a significant increase in MMP-2 activity and up-regulation of ECM components and remodeling enzymes in the plantaris muscles of wild-type mice. However, MMP-2 knockout mice developed significantly less hypertrophy and ECM remodeling in response to overload compared to their wild-type littermates. Investigation of protein synthesis rate and Akt/mTOR signaling revealed no difference between wild-type and MMP-2 knockout mice, suggesting that a difference in hypertrophy was independent of protein synthesis.

CONCLUSION

taken together, our results suggest that MMP-2 is a key mediator of ECM remodeling in the setting of skeletal muscle hypertrophy.

OBJECTIVE

To assess how a checklist reminding clinicians to deliver a bundled intervention affects contraceptive knowledge and use 3 months after women seek walk-in pregnancy testing.

METHODS

Pre-intervention, an inner-city family planning clinic provided unstructured care; during the intervention period, clinic staff used a checklist to ensure women received needed services. Women seeking walk-in pregnancy testing who wished to avoid pregnancy for at least 6 months were asked to complete surveys about their contraceptive knowledge and use immediately after and 3-months after visiting the study clinic. To assess the significance of changes over time, we used logistic regression models.

RESULTS

Between January 2011 and May 2013, over 1500 women sought pregnancy testing from the study clinic; 323 completed surveys (95 pre-intervention and 228 during the intervention period). With this checklist intervention, participants were more likely to receive emergency contraception (EC) (22% vs. 5%, [aOR 4.66 (1.76-12.35)], [corrected] have an intrauterine device or implant placed at the time of their clinic visit (5% vs. 0%, p=0.02), or receive a contraceptive prescription (23% vs. 10%, p<0.001). Three months after visiting the study clinic, participants from the intervention period were more knowledgeable about intrauterine and subdermal contraception and were more likely to report at 3-month follow-up a method of contraception more effective than the method they used prior to seeking pregnancy testing from the study clinic (aOR=2.02, 95% CI=1.03-3.96). The authors would like to apologize for any inconvenience caused. [corrected].

CONCLUSIONS

Women seeking walk-in pregnancy testing appear more likely to receive EC and to have switched to a more effective form of birth control in the 3 months following their visit when clinic staff used a 3-item checklist and provided scripted counseling.

IMPLICATIONS

A checklist reminding clinic staff to assess pregnancy intentions, provide scripted counseling about both emergency and highly-effective reversible contraception, and offer same-day contraceptive initiation to women seeking walk-in pregnancy testing appears to increase use of more effective contraception.

RATIONALE

Beryllium continues to have a wide range of industrial applications. Exposure to beryllium can lead to sensitization (BeS) and chronic beryllium disease (CBD).

OBJECTIVES

The purpose of this statement is to increase awareness and knowledge about beryllium exposure, BeS, and CBD.

METHODS

Evidence was identified by a search of MEDLINE. The committee then summarized the evidence, drew conclusions, and described their approach to diagnosis and management.

MAIN RESULTS

The beryllium lymphocyte proliferation test is the cornerstone of both medical surveillance and the diagnosis of BeS and CBD. A confirmed abnormal beryllium lymphocyte proliferation test without evidence of lung disease is diagnostic of BeS. BeS with evidence of a granulomatous inflammatory response in the lung is diagnostic of CBD. The determinants of progression from BeS to CBD are uncertain, but higher exposures and the presence of a genetic variant in the HLA-DP β chain appear to increase the risk. Periodic evaluation of affected individuals can detect disease progression (from BeS to CBD, or from mild CBD to more severe CBD). Corticosteroid therapy is typically administered when a patient with CBD exhibits evidence of significant lung function abnormality or decline.

CONCLUSIONS

Medical surveillance in workplaces that use beryllium-containing materials can identify individuals with BeS and at-risk groups of workers, which can help prioritize efforts to reduce inhalational and dermal exposures.