Lake Research Partners

The deformability of red blood cells is an essential parameter that controls the rheology of blood as well as its circulation in the body. Characterizing the rigidity of the cells and their heterogeneity in a blood sample is thus a key point in the understanding of occlusive phenomena, particularly in the case of erythrocytic diseases in which healthy cells coexist with pathological cells. However, measuring intracellular rheology in small biological compartments requires the development of specific techniques. We propose a technique based on molecular rotors-viscosity-sensitive fluorescent probes-to evaluate the above key point. DASPI molecular rotor has been identified with spectral fluorescence properties decoupled from those of hemoglobin, the main component of the cytosol. After validation of the rotor as a viscosity probe in model fluids, we showed by confocal microscopy that, in addition to binding to the membrane, the rotor penetrates spontaneously and uniformly into red blood cells. Experiments conducted on temperature-stiffened red blood cells show that molecular rotors can probe their overall rigidity. A simple model allowed us to separate the contribution of the cytosol from that of the membrane, providing a quantification of cytosol rigidification with temperature, consistent with independent measurements of the viscosity of hemoglobin solutions. Our experiments demonstrate that the rotor can be used to quantify the intracellular rheology of red blood cells at the cellular level, as well as the heterogeneity of this stiffness in a blood sample. This technique opens up new possibilities for biomedical applications, diagnosis and disease monitoring.

The prevalence of drug use is at alarmingly high levels in the United States. Of particular concern is prenatal drug use, which exposes the underdeveloped organ systems of the fetus to harsh chemicals. Identifying factors associated with illicit drug use during pregnancy is critical to identify and treat at-risk pregnant women and improve maternal and infant health outcomes. The goal of this study was to examine the association between unmet mental health care needs and substance use during pregnancy. The present cross-sectional study analyzed secondary data from the 2002 to 2014 National Survey on Drug Use and Health (n = 10,516). The main outcome of interest was self-reported illicit drug use in the last 30 days. The independent variable was unmet mental health care needs in the last 12 months. Overall, 6.4% of the participants reported a history of unmet mental health care needs and 4.5% used a substance during pregnancy. The odds of illicit drug use during pregnancy were higher among women who had an unmet mental health care needs compared to women without a history of unmet mental health care needs, multivariable-adjusted odds ratio (95% CI) 4.06 (3.01 to 5.48; P < 0.001). The observed association between unmet mental health care needs and illicit drug use persisted in subgroup analyses by age, race/ethnicity and education. In a nationally representative cross-sectional sample of pregnant women, having unmet mental health care needs was positively associated with illicit drug use during pregnancy after adjusting for potential confounders.

Near-patient and point-of-care (POC) testing for infectious disease diagnostics is rapidly evolving. The American Academy of Microbiology convened a colloquium in October 2016 to explore the impact of near-patient and POC tests on patient outcomes, healthcare delivery models, public health, and healthcare costs. This report reviews characteristics and applications of near-patient and POC tests for infectious diseases, provides an overview of considerations pertaining to their implementation, oversight, and evaluation, and provides recommendations. As near-patient and POC testing is increasingly implemented in new settings and by non-laboratorians, clinical microbiology laboratory expertise is needed to ensure proper oversight. Utilization of trained personnel and evaluation of tests will ensure that the best-quality tests are ordered and interpreted correctly to benefit patient care.

BackgroundIn both Europe and the US, resident physician work hour reduction has been a source of controversy within academic medicine. In 2008, the Institute of Medicine (IOM) recommended a reduction in resident physician work hours. We sought to assess the American public perspective on this issue.MethodsWe conducted a national survey of 1,200 representative members of the public via random digit telephone dialing in order to describe US public opinion on resident physician work hour regulation, particularly with reference to the IOM recommendations.ResultsRespondents estimated that resident physicians currently work 12.9-h shifts (95% CI 12.5 to 13.3 h) and 58.3-h work weeks (95% CI 57.3 to 59.3 h). They believed the maximum shift duration should be 10.9 h (95% CI 10.6 to 11.3 h) and the maximum work week should be 50 h (95% CI 49.4 to 50.8 h), with 1% approving of shifts lasting >24 h (95% CI 0.6% to 2%). A total of 81% (95% CI 79% to 84%) believed reducing resident physician work hours would be very or somewhat effective in reducing medical errors, and 68% (95% CI 65% to 71%) favored the IOM proposal that resident physicians not work more than 16 h over an alternative IOM proposal permitting 30-h shifts with ≥5 h protected sleep time. In all, 81% believed patients should be informed if a treating resident physician had been working for >24 h and 80% (95% CI 78% to 83%) would then want a different doctor.ConclusionsThe American public overwhelmingly favors discontinuation of the 30-h shifts without protected sleep routinely worked by US resident physicians and strongly supports implementation of restrictions on resident physician work hours that are as strict, or stricter, than those proposed by the IOM. Strong support exists to restrict resident physicians' work to 16 or fewer consecutive hours, similar to current limits in New Zealand, the UK and the rest of Europe.