Correlation of Maximal Inspiratory Pressure to Transdiaphragmatic Twitch Pressure in Intensive Care Unit Patients

Background: Respiratory muscle weakness contributes to respiratory failure in ICU patients. Unfortunately, assessment of weakness is difficult since the most objective test, transdiaphragmatic pressure in response to phrenic nerve stimulation (PdiTw), is difficult to perform. While most clinicians utilize maximum inspiratory pressure (Pimax) to assess strength, the relationship of this index to PdiTw has not been evaluated in a large ICU population. The purpose of the present study was to assess both PdiTw and Pimax in ICU patients to determine how these indices correlate with each other, what factors influence these indices, and how well these indices predict outcomes. Methods: Studies were performed on adult mechanically ventilated patients in the University of Kentucky MICU (n = 60). We assessed PdiTw by measuring transdiaphragmatic pressure (Pdi) in response to bilateral twitch stimulation of the phrenic nerves using dual magnetic stimulators (Magstim 200). Pimax was determined by measuring airway pressure during a 30-second inspiratory occlusion. We also assessed the twitch and maximum force generation for diaphragms excised from control and septic mice. Results: Both Pimax and PdiTw measurements were profoundly reduced for mechanically ventilated MICU patients when compared to normal reference values, e.g., Pimax averaged 56 % of the predicted value for normal subjects. For the ICU population as a whole, PdiTw and Pimax values correlated with each other (r2 = 0.373, p \u3c 0.001), but there was wide scatter and, as a result, PdiTw could not be reliably calculated from Pimax levels for individual subjects. Infection selectively reduced low-frequency force generation more than high-frequency force generation for both our mouse experiments (comparing muscle twitch to 150 Hz tetanic force) and for MICU patients (comparing PdiTw to Pimax). This effect of infection may contribute to scatter in the PdiTw to Pimax relationship. We also found that both PdiTw and Pimax were significantly correlated with both patient survival and the duration of mechanical ventilation, albeit statistically, PdiTw was the better predictor. Conclusions: While more difficult to measure, the PdiTw is a better predictor of outcomes in mechanically ventilated MICU patients than the Pimax. Nevertheless, for some clinical applications, the Pimax determination is a reasonable alternative

A Randomized Controlled Trial to Determine Whether Beta-Hydroxy-Beta-Methylbutyrate and/or Eicosapentaenoic Acid Improves Diaphragm and Quadriceps Strength in Critically Ill Mechanically Ventilated Patients

BACKGROUND: Intensive care unit acquired weakness is a serious problem, contributing to respiratory failure and reductions in ambulation. Currently, there is no pharmacological therapy for this condition. Studies indicate, however, that both beta-hydroxy-beta-methylbutyrate (HMB) and eicosapentaenoic acid (EPA) increase muscle function in patients with cancer and in older adults. The purpose of this study was to determine whether HMB and/or EPA administration would increase diaphragm and quadriceps strength in mechanically ventilated patients. METHODS: Studies were performed on 83 mechanically ventilated patients who were recruited from the Medical Intensive Care Units at the University of Kentucky. Diaphragm strength was assessed as the trans-diaphragmatic pressure generated by supramaximal magnetic phrenic nerve stimulation (PdiTw). Quadriceps strength was assessed as leg force generated by supramaximal magnetic femoral nerve stimulation (QuadTw). Diaphragm and quadriceps thickness were assessed by ultrasound. Baseline measurements of muscle strength and size were performed, and patients were then randomized to one of four treatment groups (placebo, HMB 3 gm/day, EPA 2 gm/day and HMB plus EPA). Strength and size measurements were repeated 11 days after study entry. ANCOVA statistical testing was used to compare variables across the four experimental groups. RESULTS: Treatments failed to increase the strength and thickness of either the diaphragm or quadriceps when compared to placebo. In addition, treatments also failed to decrease the duration of mechanical ventilation after study entry. CONCLUSIONS: These results indicate that a 10-day course of HMB and/or EPA does not improve skeletal muscle strength in critically ill mechanically ventilated patients. These findings also confirm previous reports that diaphragm and leg strength in these patients are profoundly low. Additional studies will be needed to examine the effects of other anabolic agents and innovative forms of physical therapy. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01270516. Registered 5 January 2011, https://clinicaltrials.gov/ct2/show/NCT01270516?term=Supinski&draw=2&rank=4

Health-Related Quality of Life in Adults From 17 Family Practice Clinics in North Carolina

Introduction: We examined health-related quality of life (HRQOL) in white and African American patients based on their own and their community's socioeconomic status. Methods: Participants were 4,565 adults recruited from 17 family physician practices in urban and rural areas of North Carolina. Education was used as a proxy for individual socioeconomic status, and the census block-group poverty level was used as a proxy for community socioeconomic status. HRQOL measures were the 12-Item Short Form Survey Instrument, physical component summary (PCS) and mental component summary (MCS), and 3 Centers for Disease Control and Prevention HRQOL healthy days measures. Multilevel analyses examined independent associations of individual and community poverty level with HRQOL, adjusting for demographics and clustering by family practice. Analyses were stratified by race and were conducted on subgroups of arthritis and cardiovascular disease patients. Results: Among whites, all 5 HRQOL measures were significantly associated with the lowest individual socioeconomic status, and 4 HRQOL measures were associated with the lowest community socioeconomic status (MCS being the exception). Among African Americans, 4 HRQOL measures were significantly associated with the lowest individual socioeconomic status and the lowest community socioeconomic status (PCS being the exception). Arthritis and cardiovascular disease subgroup analyses showed generally analogous findings. Conclusion: Better HRQOL measures generally were associated with low levels of community poverty and high levels of education, emphasizing the need for further exploration of factors that influence health

Use of Complementary and Alternative Medicine Among Patients With Arthritis

Introduction: Previous studies suggest that people with arthritis have high rates of using complementary and alternative medicine (CAM) approaches for managing their arthritis, in addition to conventional treatments such as prescription medications. However, little is known about the use of CAM by diagnosis, or which forms of CAM are most frequently used by people with arthritis. This study was designed to provide detailed information about use of CAM for symptoms associated with arthritis in patients followed in primary care and specialty clinics in North Carolina. Methods: Using a cross-sectional design, we drew our sample from primary care (n = 1,077) and specialist (n = 1,063) physician offices. Summary statistics were used to calculate differences within and between diagnostic groups, practice settings, and other characteristics. Logistic regression models clustered at the site level were used to determine the effect of patient characteristics on ever and current use of 9 CAM categories and an overall category of "any use." Results: Most of the participants followed by specialists (90.5%) and a slightly smaller percentage of those in the primary care sample (82.8%) had tried at least 1 complementary therapy for arthritis symptoms. Participants with fibromyalgia used complementary therapies more often than those with rheumatoid arthritis, osteoarthritis, or chronic joint symptoms. More than 50% of patients in both samples used over-the-counter topical pain relievers, more than 25% used meditation or drew on religious or spiritual beliefs, and more than 19% used a chiropractor. Women and participants with higher levels of education were more likely to report current use of alternative therapies. Conclusion: Most arthritis patients in both primary care and specialty settings have used CAM for their arthritis symptoms. Health care providers (especially musculoskeletal specialists) should discuss these therapies with all arthritis patients

“Hello Central, Give Me Doctor Jazz”: Auto/Ethnographic Improvisation as Educational Event in Doctoral Supervision

Through exchanges within a doctoral supervision, the authors explore a range of dilemmas and challenges for reflexive inquiry. These include the problematic business of naming, the impossibility of objective separation of self from research, the merging of researcher subjectivities, and differences between performance and performativity. We note the educational potential in what can conventionally be considered “unprofessional” approaches to qualitative inquiry: neologisms, personal experience, stories, conversations, music, poetry, paintings, and film. We engage in reflexive interactions with each other and with such “data.” This was undertaken in the spirit of jazz improvisation—an unrehearsed performance—something that “happened,” an unplanned educational event but also an agency enabled by structure

Paths Explored, Paths Omitted, Paths Obscured: Decision Points & Selective Reporting in End-to-End Data Analysis

Drawing reliable inferences from data involves many, sometimes arbitrary, decisions across phases of data collection, wrangling, and modeling. As different choices can lead to diverging conclusions, understanding how researchers make analytic decisions is important for supporting robust and replicable analysis. In this study, we pore over nine published research studies and conduct semi-structured interviews with their authors. We observe that researchers often base their decisions on methodological or theoretical concerns, but subject to constraints arising from the data, expertise, or perceived interpretability. We confirm that researchers may experiment with choices in search of desirable results, but also identify other reasons why researchers explore alternatives yet omit findings. In concert with our interviews, we also contribute visualizations for communicating decision processes throughout an analysis. Based on our results, we identify design opportunities for strengthening end-to-end analysis, for instance via tracking and meta-analysis of multiple decision paths

LSST: from Science Drivers to Reference Design and Anticipated Data Products

(Abridged) We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). A vast array of science will be enabled by a single wide-deep-fast sky survey, and LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. LSST will be a wide-field ground-based system sited at Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg$^2$ field of view, and a 3.2 Gigapixel camera. The standard observing sequence will consist of pairs of 15-second exposures in a given field, with two such visits in each pointing in a given night. With these repeats, the LSST system is capable of imaging about 10,000 square degrees of sky in a single filter in three nights. The typical 5$\sigma$ point-source depth in a single visit in $r$ will be $\sim 24.5$ (AB). The project is in the construction phase and will begin regular survey operations by 2022. The survey area will be contained within 30,000 deg$^2$ with $\delta<+34.5^\circ$, and will be imaged multiple times in six bands, $ugrizy$, covering the wavelength range 320--1050 nm. About 90\% of the observing time will be devoted to a deep-wide-fast survey mode which will uniformly observe a 18,000 deg$^2$ region about 800 times (summed over all six bands) during the anticipated 10 years of operations, and yield a coadded map to $r\sim27.5$. The remaining 10\% of the observing time will be allocated to projects such as a Very Deep and Fast time domain survey. The goal is to make LSST data products, including a relational database of about 32 trillion observations of 40 billion objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures available from https://www.lsst.org/overvie

Communications Biophysics

Contains research objectives, summary of research and reports on four research projects.National Institutes of Health (Grant 5 P01 GM14940-05)National Institutes of Health (Grant 5 TOl GM01555-05)National Aeronautics and Space Administration (Grant NGL 22-009-304)B-D ElectrodyneBoston City Hospital Purchase Order 1065

Efficacy and Safety of an Injectable Combination Hormonal Contraceptive for Men

CONTEXT: The development of a safe and effective reversible method of male contraception is still an unmet need. OBJECTIVE: Evaluation of suppression of spermatogenesis and contraceptive protection by coadministered im injections of progestogen and testosterone. DESIGN: Prospective multicentre study. SETTING: Ten study centers. PARTICIPANTS: Healthy men, aged 18-45 years, and their 18- to 38-year-old female partners, both without known fertility problems. INTERVENTION: Intramuscular injections of 200-mg norethisterone enanthate combined with 1000-mg testosterone undecanoate, administered every 8 weeks. MAIN OUTCOMES MEASURES: Suppression of spermatogenesis by ejaculate analysis, contraceptive protection by pregnancy rate. RESULTS: Of the 320 participants, 95.9 of 100 continuing users (95% confidence interval [CI], 92.8-97.9) suppressed to a sperm concentration less than or equal to 1 million/mL within 24 weeks (Kaplan-Meier method). During the efficacy phase of up to 56 weeks, 4 pregnancies occurred among the partners of the 266 male participants, with the rate of 1.57 per 100 continuing users (95% CI, 0.59-4.14). The cumulative reversibility of suppression of spermatogenesis after 52 weeks of recovery was 94.8 per 100 continuing users (95% CI, 91.5-97.1). The most common adverse events were acne, injection site pain, increased libido, and mood disorders. Following the recommendation of an external safety review committee the recruitment and hormone injections were terminated early. CONCLUSIONS: The study regimen led to near-complete and reversible suppression of spermatogenesis. The contraceptive efficacy was relatively good compared with other reversible methods available for men. The frequencies of mild to moderate mood disorders were relatively high

ERRATUM: "DETERMINING TITAN'S SPIN STATE FROM CASSINI RADAR IMAGES" (2008, AJ, 135, 1669)

We previously reported an initial determination of Titan's rotational state from fits to overlapping radar images. We have since discovered a coding error in software used to make these fits, which led to systematic offsets of 1-2 km in recovered positions. While our principal results remain qualitatively unchanged, with this error corrected, the pole movement we previously reported (our weakest result) is now counterindicated. Our revised best fit is essentially the same as the "best-fit no pole wobble" result discussed at the top of the second column on page 1675. The determined pole location did not change significantly after the bug fix and thus we still conclude that the spin axis is not in the plane formed by Titan's orbit normal and the normal to the Laplace plane. Due to the correlations between pole wobble and spin rate (see Figure 3 on page 1672), the new best fit has a spin rate that differs from the synchronous value by an amount that is three times smaller than the value reported in the paper. The pole location changed by less than 0.01 deg (~500 m on the surface) and rate of increase in spin decreased by a factor of 2 from the previous fit. The new best-fit parameter values with 1σ error bars are: pole right ascension 39.4934 ± 0.0249 deg, pole declination 83.4368 ± 0.0024 deg, spin rate 22.57731 ± 0.00011 deg/day (0.00033 deg/day greater than synchronous spin rate), derivative of pole right ascension –6.52 ± 4.20 deg/century, derivative of pole declination –0.2212 ± 0.3567 deg/century, and derivative of spin rate 0.0247 ± 0.0050 deg/day/century. The corrected version of Table 3 (below) shows the residual systematic and random error of the several candidate models discussed in the paper. Fixing the bug reduced the residual systematic error of all the fitted models. The four models in which spin rate is allowed to vary from synchronous either due to a change in spin rate (Column 5, numbered from the left) or a change in its time derivative (Column 6) or both (Columns 7 and 8) have lower residual systematic errors and thus better represent the data than do the purely synchronous fit (Column 3). For this reason, an asynchronous spin rate is still supported by the data, although efforts (e.g., Mitchell 2009) to quantitatively interpret the asynchroneity should take our revised determination into account. On the other hand, as depicted by Columns 7 and 8, allowing the pole movement terms to vary from the predicted (IAU Titan) values results in no significant improvement in the fit, thus large short-term pole movement is not supported by the data. In fact, the best-fit values and error bars for the pole movement are consistent with the long-term pole trends that were predicted prior to the Cassini mission