Dietary Supplement Intake is Associated with Healthier Lifestyle Behaviors in College Students Attending a Regional University in the Southeast: A Cross-Sectional Study

The relationship between intake of dietary supplements and biomarkers such as insulin and insulin-like growth factor has not been well explored. The primary aim of this cross-sectional study was to investigate the associations between supplement intake and biological and lifestyle factors. We hypothesized that dietary supplement intake was associated with healthier lifestyle behaviors. College students attending a Southeast university were recruited between January 2018 and April 2019. Blood samples were collected to measure insulin, insulin-like growth factor 1 (IGF-1) and alanine aminotransferase (ALT). Statistical tests employed were linear regression and analysis of variance. Ninety-eight participants completed the study and 91% reported taking at least one supplement, while 5.1% reported taking 9+ supplements once per week. There were no differences in levels of insulin, IGF-1 and ALT by levels of dietary supplement intake. Although there were no differences in HEI-2015 score among the groups, those who consumed five or more supplements met a higher percentage of the recommended intake for fruits, performed aerobic exercise for longer duration, and had lower body fat percentage compared to participants who consumed two or less supplements at least once per week. These findings are consistent with previous studies and suggest that dietary supplement intake is highly prevalent in college students, and it may be related to healthy lifestyle behaviors. Future studies should employ mixed methodology to examine reasons by which college students consume dietary supplements and to assess perceived and direct health benefits associated with consumption.

OS01.7.A Detection of methylation-based prognostic signatures in liquid biopsy specimens from patients with meningiomas

Background

Detection of distinct epigenetic biomarkers in circulating cell-free DNA (cfDNA) of liquid biopsy (LB) specimens (e.g. blood) fosters opportunity for prognostication of central nervous system (CNS) tumors and has not been thoroughly explored in patients with meningiomas.

Material and Methods

We profiled the cfDNA methylome (EPIC array) in serum specimens from patients with meningiomas (MNG; n= 63) and harnessed internal and external meningioma tissue methylome data with reported follow up (n=48). To predict recurrence risk (RR), we consolidated a tissue cohort with at least 5 years of follow up and divided them into confirmed recurrence (CR; either reported progressive disease in post-surgical imaging, or additional resections following initial surgery) and confirmed no-recurrence (CNR: no confirmed disease progression w/in at least 5-years of follow-up). Then through application of an iterative process consisting of multiple tissue- and serum-based supervised analyses, we identified risk-specific methylation markers with serum specific features which, when inputted into a random forest algorithm allowed for segregation of both tumor tissue and liquid biopsy specimens according to recurrence risk. We estimated immune cell composition using MethylCIBERSORT, where a reference methylome atlas of chosen immune cell types was utilized to deconvolute the MNG samples.

Results

The resulting recurrence risk classifier demonstrated an appreciable predictive power in classifying samples as high or low recurrence risk across the tumor tissue cohort (ACC: 87.5%, CUI+: 85.2%). When compared to another classifier, our model demonstrated statistically significant agreement across primary meningioma samples (κ=0.269, p=0.002), and more accurately predicted samples to recur across an expanded time window (time to recurrence >5yrs). Across resulting liquid biopsy classifications, recurrence risk subgroups were analogous with reported risk factors, including WHO grade, extent of resection, and tumor location. Recurrence risk subgroups (high and low) also demonstrated differential estimated immune cell contributions, with low-risk samples exhibiting a “hot” profile, or enrichment of B-Cells, CD56- and CD4 T-Cells, and natural killer cells. Notably, the estimated neutrophil to lymphocyte ratio, previously purported to be relevant to tumor prognosis, was appreciably higher for those meningioma samples with the highest recurrence risk.

Conclusion

DNA methylation markers identified in the serum are suitable for the development of machine learning-based models which present high predictive power to prognosticate patients with meningioma and estimate a differential immune profile across recurrence risk groups. After validation in an external cohort, this noninvasive approach may improve the presurgical therapeutic management of patients with meningiomas.

Differences in obstetrical care and outcomes associated with the proportion of the obstetrician's shift completed

BACKGROUND

Understanding and improving obstetrical quality and safety is an important goal of professional societies, and many interventions such as checklists, safety bundles, educational interventions, or other culture changes have been implemented to improve the quality of care provided to obstetrical patients. Although many factors contribute to delivery decisions, a reduced workload has addressed how provider issues such as fatigue or behaviors surrounding impending shift changes may influence the delivery mode and outcomes.

OBJECTIVE

The objective was to assess whether intrapartum obstetrical interventions and adverse outcomes differ based on the temporal proximity of the delivery to the attending's shift change.

STUDY DESIGN

This was a secondary analysis from a multicenter obstetrical cohort in which all patients with cephalic, singleton gestations who attempted vaginal birth were eligible for inclusion. The primary exposure used to quantify the relationship between the proximity of the provider to their shift change and a delivery intervention was the ratio of time from the most recent attending shift change to vaginal delivery or decision for cesarean delivery to the total length of the shift. Ratios were used to represent the proportion of time completed in the shift by normalizing for varying shift lengths. A sensitivity analysis restricted to patients who were delivered by physicians working 12-hour shifts was performed. Outcomes chosen included cesarean delivery, episiotomy, third- or fourth-degree perineal laceration, 5-minute Apgar score of <4, and neonatal intensive care unit admission. Chi-squared tests were used to evaluate outcomes based on the proportion of the attending's shift completed. Adjusted and unadjusted logistic models fitting a cubic spline (when indicated) were used to determine whether the frequency of outcomes throughout the shift occurred in a statistically significant, nonlinear pattern RESULTS: Of the 82,851 patients eligible for inclusion, 47,262 (57%) had ratio data available and constituted the analyzable sample. Deliveries were evenly distributed throughout shifts, with 50.6% taking place in the first half of shifts. There were no statistically significant differences in the frequency of cesarean delivery, episiotomy, third- or fourth-degree perineal lacerations, or 5-minute Apgar scores of <4 based on the proportion of the shift completed. The findings were unchanged when evaluated with a cubic spline in unadjusted and adjusted logistic models. Sensitivity analyses performed on the 22.2% of patients who were delivered by a physician completing a 12-hour shift showed similar findings. There was a small increase in the frequency of neonatal intensive care unit admissions with a greater proportion of the shift completed (adjusted P=.009), but the findings did not persist in the sensitivity analysis.

CONCLUSION

Clinically significant differences in obstetrical interventions and outcomes do not seem to exist based on the temporal proximity to the attending physician's shift change. Future work should attempt to directly study unit culture and provider fatigue to further investigate opportunities to improve obstetrical quality of care, and additional studies are needed to corroborate these findings in community settings.

Changes in Myocardial Metabolism Preceding Sudden Cardiac Death

Heart disease is widely recognized as a major cause of death worldwide and is the leading cause of mortality in the United States. Centuries of research have focused on defining mechanistic alterations that drive cardiac pathogenesis, yet sudden cardiac death (SCD) remains a common unpredictable event that claims lives in every age group. The heart supplies blood to all tissues while maintaining a constant electrical and hormonal feedback communication with other parts of the body. As such, recent research has focused on understanding how myocardial electrical and structural properties are altered by cardiac metabolism and the various signaling pathways associated with it. The importance of cardiac metabolism in maintaining myocardial function, or lack thereof, is exemplified by shifts in cardiac substrate preference during normal development and various pathological conditions. For instance, a shift from fatty acid (FA) oxidation to oxygen-sparing glycolytic energy production has been reported in many types of cardiac pathologies. Compounded by an uncoupling of glycolysis and glucose oxidation this leads to accumulation of undesirable levels of intermediate metabolites. The resulting accumulation of intermediary metabolites impacts cardiac mitochondrial function and dysregulates metabolic pathways through several mechanisms, which will be reviewed here. Importantly, reversal of metabolic maladaptation has been shown to elicit positive therapeutic effects, limiting cardiac remodeling and at least partially restoring contractile efficiency. Therein, the underlying metabolic adaptations in an array of pathological conditions as well as recently discovered downstream effects of various substrate utilization provide guidance for future therapeutic targeting. Here, we will review recent data on alterations in substrate utilization in the healthy and diseased heart, metabolic pathways governing cardiac pathogenesis, mitochondrial function in the diseased myocardium, and potential metabolism-based therapeutic interventions in disease.

A Pilot Study of a Videoconferencing-Based Binge Eating Disorder Program in Overweight or Obese Females

Background: There has been increasing interest in using videoconferencing in health care, but limited research was conducted in Binge Eating Disorder (BED) patients. This 3-month pilot study aimed to assess the feasibility, acceptability, and preliminary efficacy of a videoconferencing (VC)-based treatment program in overweight and obese females with BED. Methods: Eighteen participants, aged 20-73, were diagnosed and randomized into either a face-to-face (F2F) group or a VC-based group. In the F2F group, participants received 12 one-on-one weekly counseling sessions from a Licensed Mental Health Counselor and Registered Dietitian Nutritionist. In the VC group, participants received the same counseling through an online telemedicine software. Measured outcomes include retention, adherence to treatment, and attitudinal and behavioral changes of participants. Results: In the end of study, of the 9 participants randomized into each group, 8 (88.9%) F2F participants and 4 (44.4%) VC participants completed the study. On average, F2F finishers attended 94.8% of sessions and completed 66.2% of dietary diaries. VC finishers attended 95.8% of sessions and completed 55.4% of diaries. No changes in weight and binge eating episode were observed in either group. F2F finishers had significant improvement on uncontrolled eating (p = 0.01), emotional eating (p = 0.004), food addiction diagnosis (p = 0.04), loss of control (p = 0.04), and clinical significance (p = 0.04). VC finishers observed significant improvements in eating disorder examination shape concern (p = 0.03) and global score (p = 0.03). Conclusion: VC-based treatment program is feasible and could be effective for BED patients. Long-term large-scale randomized clinical trials are warranted to further assess the efficacy.

P01.02 Serum-derived DNA methylation markers distinguish functional and invasiveness subtypes in patients harboring pituitary tumors

BACKGROUND

Molecular profiling of circulating biomarkers released by tumors has a relevant clinical value in central nervous system (CNS) tumors, but its feasibility has not been investigated in pituitary tumors (PT) despite being the second common intraaxial tumors of the CNS (~15%). Although usually benign and slow-growing, they can be nonfunctioning and invade surrounding structures resulting in significant comorbidities. DNA methylation aberrations distinguish PT according to their functional status but their role in invasiveness is still unclear. Pre-surgical detection of clinically relevant molecular markers associated with tumor behavior can address current diagnostic and therapeutic challenges. We hypothesized that PT release cell-free DNA (cfDNA) into the bloodstream allowing for the profiling of epigenetic markers associated with relevant clinicopathological features.

MATERIAL AND METHODS

Genome-wide methylome profile of paired serum cfDNA (EPIC array) and tissue from 13 patients with pituitary macroadenomas (9 males; median age: 62; 9 NFPT, 6 invasive) and 3 controls serum (patients with epilepsy).

RESULTS

Unsupervised analysis of the serum methylome from patients harboring PT was distinct from controls and other diseases (hypopituitarism, glioma and colorectal cancer) and supervised analysis (Wilcoxon Rank-sum Test) identified significant differentially methylated probes (DMP) that segregated PT from control serum specimens. Nonfunctioning and invasive-specific DMPs identified in the serum also defined functional, and less prominently invasive status, in the tissue of an independent cohort of PT.

CONCLUSION

This is the first study to show the feasibility to profile the methylome in the serum of patients with PT using cfDNA. In addition, we identified unique methylation signatures that distinguished PT according to functional and invasiveness subtypes. These results underpin the potential role of methylation profile and liquid biopsy as a noninvasive approach to assess clinically relevant molecular features in the serum of patients harboring PT.

OS1.5 Detection of glioma and prognostic subtypes by non-invasive circulating cell-free DNA methylation markers

BACKGROUND: Genome-wide DNA methylation profiling has shown that epigenetic abnormalities are biologically important in glioma and can be used to classify these tumors into distinct prognostic groups. Thus far, DNA profiling has required surgically resected glioma tissue; however, gliomas release tumoral material into biofluids providing an opportunity for a minimally invasive testing. While prior studies have shown that molecular markers can be detected in liquid biopsy (LB), there has been low sensitivity for tumor-specific markers. We hypothesize that the low sensitivity is due to the targeted assay methods. METHODS: Genome-wide CpG methylation levels in DNA of tumor tissue and cell-free DNA serum of glioma patients. RESULTS: We defined glioma-specific and IDH-specific epigenetic LB (eLB) signatures (Glioma-eLB and IDH-eLB, respectively) from serum cell-free DNA from patients diagnosed with glioma (N=15 IDH mutant and N=7 IDH wildtype) and with epilepsy (N=3). The epigenetic profiles of the matched tissue demonstrate that these eLB signatures reflected the signature of the tumor. Through cross-validation we show that Glioma-eLB can accurately predict a patient’s glioma from those with other neoplasias (N=6 Colon; N=14 Pituitary; N=3 Breast; N=4 Lung), non-neoplastic immunological conditions (N=22 sepsis; N=9 pancreatic islet transplantation), and from healthy individuals (sensitivity: 98%; specificity: 99%). Finally, IDH-eLB includes promoter methylated markers associated with genes known to be involved in glioma tumorigenesis (PVT1 and CXCR6). CONCLUSIONS: The application of the non-invasive eLB signature discovered in this study has the potential to complement the standard of care for patients harboring glioma.

This project is supported by the Henry Ford Health System, Department of Neurosurgery and the Hermelin Brain Tumor Center Foundation (A30935), United States National Institutes of Health (R01CA222146), and United States Department of Defense (CA170278)

Effects of a Web-based Binge Eating Disorder Intervention Program on Depression and Quality of Life in Overweight or Obese Females (P16-065-19)

Objectives

Web-based treatment programs have shown encouraging results in reducing symptoms in Binge Eating Disorder (BED) patients in European studies but no significant studies have been conducted with American subjects. This pilot randomized controlled trial aimed to assess the efficacy of a web-based outpatient treatment program in overweight and obese females diagnosed with BED in the United States.

Methods

A total of 12 overweight or obese women with BED, aged 20–73, were analyzed in this study. In face-to-face (FF) group (n = 8), participants received a total 12 one-on-one weekly counseling from either a mental health counselor or a Registered Dietitian (RD) sessions. In web-based (WB) group (n = 4), participants received the same counseling through an online telemedicine software program. Outcomes were measured at 3 months including questionnaires SCL-90R (Symptom Checklist 90 Revised), BDI-II (Beck Depression Inventory II), and IWQOL-Lite (Impact of Weight on Quality of Life – short form) assessing psychological health, and quality of life. Between group and within group differences were examined.

Results

In the end of study, significant improvements were observed in WB group for SCL-90R depression scale (P = 0.000), and IWQOL total score (P = 0.02). There were no significant changes in FF participants. There were no differences between two groups in the end of program neither.

Conclusions

Web-based treatment programs could potentially be an effective approach for binge eating disorder patients. Large scale randomized clinical trials are warranted to further assess the efficacy of web-based approaches in treating eating disorders.

Funding Sources

Us Women and Girls’ Health Endowed Research Professorship; Complimentary telemedicine software from Fruit Street company.

Neonatal outcomes of elective early-term births after demonstrated fetal lung maturity

BACKGROUND

Studies of early-term birth after demonstrated fetal lung maturity show that respiratory and other outcomes are worse with early-term birth (37⁰-38⁶ weeks) even after demonstrated fetal lung maturity when compared with full-term birth (39⁰-40⁶ weeks). However, these studies included medically indicated births and are therefore potentially limited by confounding by the indication for delivery. Thus, the increase in adverse outcomes might be due to the indication for early-term birth rather than the early-term birth itself.

OBJECTIVE

We examined the prevalence and risks of adverse neonatal outcomes associated with early-term birth after confirmed fetal lung maturity as compared with full-term birth in the absence of indications for early delivery.

STUDY DESIGN

This is a secondary analysis of an observational study of births to 115,502 women in 25 hospitals in the United States from 2008 through 2011. Singleton nonanomalous births at 37-40 weeks with no identifiable indication for delivery were included; early-term births after positive fetal lung maturity testing were compared with full-term births. The primary outcome was a composite of death, ventilator for ≥2 days, continuous positive airway pressure, proven sepsis, pneumonia or meningitis, treated hypoglycemia, hyperbilirubinemia (phototherapy), and 5-minute Apgar <7. Logistic regression and propensity score matching (both 1:1 and 1:2) were used.

RESULTS

In all, 48,137 births met inclusion criteria; the prevalence of fetal lung maturity testing in the absence of medical or obstetric indications for early delivery was 0.52% (n = 249). There were 180 (0.37%) early-term births after confirmed pulmonary maturity and 47,957 full-term births. Women in the former group were more likely to be non-Hispanic white, smoke, have received antenatal steroids, have induction, and have a cesarean. Risks of the composite (16.1% vs 5.4%; adjusted odds ratio, 3.2; 95% confidence interval, 2.1-4.8 from logistic regression) were more frequent with elective early-term birth. Propensity scores matching confirmed the increased primary composite in elective early-term births: adjusted odds ratios, 4.3 (95% confidence interval, 1.8-10.5) for 1:1 and 3.5 (95% confidence interval, 1.8-6.5) for 1:2 matching. Among components of the primary outcome, CPAP use and hyperbilirubinemia requiring phototherapy were significantly increased. Transient tachypnea of the newborn, neonatal intensive care unit admission, and prolonged neonatal intensive care unit stay (>2 days) were also increased with early-term birth.

CONCLUSION

Even with confirmed pulmonary maturity, early-term birth in the absence of medical or obstetric indications is associated with worse neonatal respiratory and hepatic outcomes compared with full-term birth, suggesting relative immaturity of these organ systems in early-term births.

Preterm neonatal morbidity and mortality by gestational age: a contemporary cohort

BACKGROUND

Although preterm birth <37 weeks' gestation is the leading cause of neonatal morbidity and mortality in the United States, the majority of data regarding preterm neonatal outcomes come from older studies, and many reports have been limited to only very preterm neonates. Delineation of neonatal outcomes by delivery gestational age is needed to further clarify the continuum of mortality and morbidity frequencies among preterm neonates.

OBJECTIVE

We sought to describe the contemporary frequencies of neonatal death, neonatal morbidities, and neonatal length of stay across the spectrum of preterm gestational ages.

STUDY DESIGN

This was a secondary analysis of an obstetric cohort of 115,502 women and their neonates who were born in 25 hospitals nationwide, 2008 through 2011. All liveborn nonanomalous singleton preterm (23.0-36.9 weeks of gestation) neonates were included in this analysis. The frequency of neonatal death, major neonatal morbidity (intraventricular hemorrhage grade III/IV, seizures, hypoxic-ischemic encephalopathy, necrotizing enterocolitis stage II/III, bronchopulmonary dysplasia, persistent pulmonary hypertension), and minor neonatal morbidity (hypotension requiring treatment, intraventricular hemorrhage grade I/II, necrotizing enterocolitis stage I, respiratory distress syndrome, hyperbilirubinemia requiring treatment) were calculated by delivery gestational age; each neonate was classified once by the worst outcome for which criteria was met.

RESULTS

In all, 8334 deliveries met inclusion criteria. There were 119 (1.4%) neonatal deaths. In all, 657 (7.9%) neonates had major morbidity, 3136 (37.6%) had minor morbidity, and 4422 (53.1%) survived without any of the studied morbidities. Deaths declined rapidly with each advancing week of gestation. This decline in death was accompanied by an increase in major neonatal morbidity, which peaked at 54.8% at 25 weeks of gestation. As frequencies of death and major neonatal morbidity fell, minor neonatal morbidity increased, peaking at 81.7% at 31 weeks of gestation. The frequency of all morbidities fell >32 weeks. After 25 weeks, neonatal length of hospital stay decreased significantly with each additional completed week of pregnancy; among babies delivered from 26-32 weeks of gestation, each additional week in utero reduced the subsequent length of neonatal hospitalization by a minimum of 8 days. The median postmenstrual age at discharge nadired around 36 weeks' postmenstrual age for babies born at 31-35 weeks of gestation.

CONCLUSION

Our data show that there is a continuum of outcomes, with each additional week of gestation conferring survival benefit while reducing the length of initial hospitalization. These contemporary data can be useful for patient counseling regarding preterm outcomes.

Experimental capabilities of 0.4 PW, 1 shot/min Scarlet laser facility for high energy density science

We report on the recently completed 400 TW upgrade to the Scarlet laser at The Ohio State University. Scarlet is a Ti:sapphire-based ultrashort pulse system that delivers >10  J in 30 fs pulses to a 2 μm full width at half-maximum focal spot, resulting in intensities exceeding 5×10²¹  W/cm². The laser fires at a repetition rate of once per minute and is equipped with a suite of on-demand and on-shot diagnostics detailed here, allowing for rapid collection of experimental statistics. As part of the upgrade, the entire laser system has been redesigned to facilitate consistent, characterized high intensity data collection at high repetition rates. The design and functionality of the laser and target chambers are described along with initial data from commissioning experimental shots.

Microengineering Laser Plasma Interactions at Relativistic Intensities

We report on the first successful proof-of-principle experiment to manipulate laser-matter interactions on microscales using highly ordered Si microwire arrays. The interaction of a high-contrast short-pulse laser with a flat target via periodic Si microwires yields a substantial enhancement in both the total and cutoff energies of the produced electron beam. The self-generated electric and magnetic fields behave as an electromagnetic lens that confines and guides electrons between the microwires as they acquire relativistic energies via direct laser acceleration.

The impact of a cadaver-based airway lab on critical care fellows' direct laryngoscopy skills

This study sought to determine the impact of a cadaver-based airway lab on critical care medicine fellows' direct laryngoscopy skills and hypothesised that fellows can improve their self-reported percentage of glottic opening (POGO) scores in cadaver models to achieve POGO scores similar to that of expert faculty. Nineteen fellows attended an airway management skills laboratory utilising five modified cadavers. Initial fellow POGO (POGOi) visualised was recorded at the onset with direct laryngoscopy. Maximum fellow POGO score with optimised direct laryngoscopy was recorded after two additional hours of teaching and also during a testing phase several days later. Data was assessed for significant differences between trainee POGO scores at each time interval and between trainee POGO scores and expert scores. A departmental procedural database was utilised to examine success rates of intubation as a clinical correlation. Fellows' mean POGOi scores, averaged across all five specimens, were significantly lower than both their maximum POGO scores and their testing phase POGO scores. Mean POGOi scores for fellows, averaged over all five cadavers, were lower than the instructors' POGOi scores. There was no difference between fellows' and instructors' mean maximum POGO or mean testing phase POGO scores. Clinical success rates of intubation were over 98%. A short training session using modified cadavers can be utilised to teach new critical care medicine fellows additional techniques for airway management and assist them in obtaining higher POGO scores, similar to those of expert instructors. Success rates of clinical intubations were favourable in the wake of this training.

Nonmedically indicated induction vs expectant treatment in term nulliparous women

OBJECTIVE

The purpose of this study was to compare maternal and neonatal outcomes in nulliparous women with nonmedically indicated inductions at term vs those expectantly treated.

STUDY DESIGN

Data were obtained from maternal and neonatal charts for all deliveries on randomly selected days across 25 US hospitals over a 3-year period. A low-risk subset of nulliparous women with vertex nonanomalous singleton gestations who delivered 38 0/7 to 41 6/7 weeks were selected. Maternal and neonatal outcomes for nonmedically indicated induction within each week were compared with women who did not undergo nonmedically indicated induction during that week. Multivariable analysis was used to adjust for hospital, maternal age, race/ethnicity, body mass index, cigarette use, and insurance status.

RESULTS

We found 31,169 women who met our criteria. Neonatal complications were either less frequent with nonmedically indicated induction or no different between groups. Nonmedically indicated induction was associated with less frequent peripartum infections (odds ratio [OR], 0.39; 95% confidence interval [CI], 0.16-0.98) at 38 weeks of gestation and less frequent third- and fourth-degree lacerations (OR, 0.60; 95% CI, 0.42-0.86) and less frequent peripartum infections (OR, 0.66; 95% CI, 0.49-0.90) at 39 weeks of gestation. Nonmedically indicated induction was associated with a longer admission-to-delivery time by approximately 3-4 hours and increased odds of cesarean delivery at 38 (OR, 1.50; 95% CI, 1.08-2.08) and 40 weeks (OR, 1.30; 95% CI, 1.15-1.46) of gestation.

CONCLUSION

At 39 weeks of gestation, nonmedically indicated induction is associated with lower maternal and neonatal morbidity than women who are expectantly treated.

Cancers among US organ donors: a comparison of transplant and cancer registry diagnoses

Transmission of cancer is a life-threatening complication of transplantation. Monitoring transplantation practice requires complete recording of donor cancers. The US Scientific Registry of Transplant Recipients (SRTR) captures cancers in deceased donors (beginning in 1994) and living donors (2004). We linked the SRTR (52,599 donors, 110,762 transplants) with state cancer registries. Cancer registries identified cancers in 519 donors: 373 deceased donors (0.9%) and 146 living donors (1.2%). Among deceased donors, 50.7% of cancers were brain tumors. Among living donors, 54.0% were diagnosed after donation; most were cancers common in the general population (e.g. breast, prostate). There were 1063 deceased donors with cancer diagnosed in the SRTR or cancer registry, and the SRTR lacked a cancer diagnosis for 107 (10.1%) of these. There were 103 living donors with cancer before or at donation, diagnosed in the SRTR or cancer registry, and the SRTR did not have a cancer diagnosis for 43 (41.7%) of these. The SRTR does not record cancers after donation in living donors and so missed 81 cancers documented in cancer registries. In conclusion, donor cancers are uncommon, but lack of documentation of some cases highlights a need for improved ascertainment and reporting by organ procurement organizations and transplant programs.

Study of two-neutron radioactivity in the decay of 26O

A new technique was developed to measure the lifetimes of neutron unbound nuclei in the picosecond range. The decay of 26O→24O+n+n was examined as it had been predicted to have an appreciable lifetime due to the unique structure of the neutron-rich oxygen isotopes. The half-life of 26O was extracted as 4.5(-1.5)(+1.1)(stat)±3(syst)  ps. This corresponds to 26O having a finite lifetime at an 82% confidence level and, thus, suggests the possibility of two-neutron radioactivity.

Unresolved question of the 10He ground state resonance

The ground state of (10)He was populated using a 2p2n-removal reaction from a 59 MeV/u (14)Be beam. The decay energy of the three-body system, (8)He+n+n, was measured and a resonance was observed at E=1.60(25) MeV with a 1.8(4) MeV width. This result is in agreement with previous invariant mass spectroscopy measurements, using the (11)Li(-p) reaction, but is inconsistent with recent transfer reaction results. The proposed explanation that the difference, about 500 keV, is due to the effect of the extended halo nature of (11)Li in the one-proton knockout reaction is no longer valid as the present work demonstrates that the discrepancy between the transfer reaction results persists despite using a very different reaction mechanism, (14)Be(-2p2n).

Apparent inverse Gibbs-Thomson effect in dealloyed nanoporous nanoparticles

The Gibbs-Thomson effect (the reduction of local chemical potential due to nanoscale curvature) predicts that nanoparticles of radius r dissolve at lower electrochemical potentials than bulk materials, decreasing as 1/r. However, we show here that if the particle is an alloy--susceptible to selective dissolution (dealloying) and nanoporosity evolution--then complete selective electrochemical dissolution and porosity evolution require a higher electrochemical potential than the comparable bulk planar material, increasing empirically as 1/r. This is a kinetic effect, which we demonstrate via kinetic Monte Carlo simulation. Our model shows that in the initial stages of dissolution, the less noble particle component is easily stripped from the nanoparticle surface, but owing to an increased mobility of the more noble atoms, the surface of the particle quickly passivates. At a fixed electrochemical potential, porosity and complete dealloying can only evolve if fluctuations in the surface passivation layer are sufficiently long-lived to allow dissolution from percolating networks of the less-noble component that penetrate through the bulk of the particle.

Evidence for the ground-state resonance of 26O

Evidence for the ground state of the neutron-unbound nucleus (26)O was observed for the first time in the single proton-knockout reaction from a 82 MeV/u (27)F beam. Neutrons were measured in coincidence with (24)O fragments. (26)O was determined to be unbound by 150(-150)(+50) keV from the observation of low-energy neutrons. This result agrees with recent shell-model calculations based on microscopic two- and three-nucleon forces.

First observation of ground state dineutron decay: 16Be

We report on the first observation of dineutron emission in the decay of 16Be. A single-proton knockout reaction from a 53  MeV/u 17B beam was used to populate the ground state of 16Be. 16Be is bound with respect to the emission of one neutron and unbound to two-neutron emission. The dineutron character of the decay is evidenced by a small emission angle between the two neutrons. The two-neutron separation energy of 16Be was measured to be 1.35(10) MeV, in good agreement with shell model calculations, using standard interactions for this mass region.

Exploring the low-Z shore of the island of inversion at n=19

The technique of invariant mass spectroscopy has been used to measure, for the first time, the ground state energy of neutron-unbound (28)F, determined to be a resonance in the (27)F+n continuum at 220(50) keV. States in (28)F were populated by the reactions of a 62 MeV/u (29)Ne beam impinging on a 288 mg/cm(2) beryllium target. The measured (28)F ground state energy is in good agreement with USDA/USDB shell model predictions, indicating that pf shell intruder configurations play only a small role in the ground state structure of (28)F and establishing a low-Z boundary of the island of inversion for N=19 isotones.

Efficacy of chlorhexidine varnish for the prevention of adult caries: a randomized trial

The Prevention of Adult Caries Study, an NIDCR-funded multicenter, double-blind, randomized clinical trial, enrolled 983 adults (aged 18-80 yrs) at high risk for developing caries (20 or more intact teeth and 2 or more lesions at screening) to test the efficacy of a chlorhexidine diacetate 10% weight per volume (w/v) dental coating (CHX). We excluded participants for whom the study treatment was contraindicated or whose health might affect outcomes or ability to complete the study. Participants were randomly assigned to receive either the CHX coating (n = 490) or a placebo control (n = 493). Coatings were applied weekly for 4 weeks and a fifth time 6 months later. The primary outcome (total net D(1-2)FS increment) was the sum of weighted counts of changes in tooth surface status over 13 months. We observed no significant difference between the two treatment arms in either the intention-to-treat or per-protocol analyses. Analysis of 3 protocol-specified secondary outcomes produced similar findings. This trial failed to find that 10% (w/v) chlorhexidine diacetate coating was superior to placebo coating for the prevention of new caries (Clinicaltrials.gov registration number NCT00357877).

Fabrication of three-dimensional scaffolds using precision extrusion deposition with an assisted cooling device

In the field of biofabrication, tissue engineering and regenerative medicine, there are many methodologies to fabricate a building block (scaffold) which is unique to the target tissue or organ that facilitates cell growth, attachment, proliferation and/or differentiation. Currently, there are many techniques that fabricate three-dimensional scaffolds; however, there are advantages, limitations and specific tissue focuses of each fabrication technique. The focus of this initiative is to utilize an existing technique and expand the library of biomaterials which can be utilized to fabricate three-dimensional scaffolds rather than focusing on a new fabrication technique. An expanded library of biomaterials will enable the precision extrusion deposition (PED) device to construct three-dimensional scaffolds with enhanced biological, chemical and mechanical cues that will benefit tissue generation. Computer-aided motion and extrusion drive the PED to precisely fabricate micro-scaled scaffolds with biologically inspired, porosity, interconnectivity and internal and external architectures. The high printing resolution, precision and controllability of the PED allow for closer mimicry of tissues and organs. The PED expands its library of biopolymers by introducing an assisting cooling (AC) device which increases the working extrusion temperature from 120 to 250 °C. This paper investigates the PED with the integrated AC's capabilities to fabricate three-dimensional scaffolds that support cell growth, attachment and proliferation. Studies carried out in this paper utilized a biopolymer whose melting point is established to be 200 °C. This polymer was selected to illustrate the newly developed device's ability to fabricate three-dimensional scaffolds from a new library of biopolymers. Three-dimensional scaffolds fabricated with the integrated AC device should illustrate structural integrity and ability to support cell attachment and proliferation.

Methods used by Dental Practice-based Research Network (DPBRN) dentists to diagnose dental caries

OBJECTIVES

To (1) identify the methods that dentists in The Dental Practice-Based Research Network (DPBRN) use to diagnose dental caries; (2) quantify their frequency of use and (3) test the hypothesis that certain dentist and dental practice characteristics are significantly associated with their use.

METHODS

A questionnaire about methods used for caries diagnosis was sent to DPBRN dentists who reported doing some restorative dentistry; 522 dentists participated. Questions included the use of dental radiographs, the dental explorer, laser fluorescence, air-drying and fiber-optic devices and magnification as used when diagnosing primary, secondary/recurrent or non-specific caries lesions. Variations on the frequency of their use were tested using multivariate analysis and Bonferroni tests.

RESULTS

Overall, the dental explorer was the instrument most commonly used to detect primary occlusal caries and caries at the margins of existing restorations. In contrast, laser fluorescence was rarely used to help diagnose occlusal primary caries. For proximal caries, radiographs were used to help diagnose 75%–100% of lesions by 96% of the DPBRN dentists. Dentists who use radiographs most often to assess proximal surfaces of posterior teeth were significantly more likely to also report providing a higher percentage of patients with individualized caries prevention (p=.040) and seeing a higher percentage of pediatric patients (p=.001).

CONCLUSION

The use of specific diagnostic methods varied substantially. The dental explorer and radiographs are still the most commonly used diagnostic methods..

Oxygen reduction in nanoporous metal-ionic liquid composite electrocatalysts

The improvement of catalysts for the four-electron oxygen-reduction reaction (ORR; O(2) + 4H(+) + 4e(-) → 2H(2)O) remains a critical challenge for fuel cells and other electrochemical-energy technologies. Recent attention in this area has centred on the development of metal alloys with nanostructured compositional gradients (for example, core-shell structure) that exhibit higher activity than supported Pt nanoparticles (Pt-C; refs 1-7). For instance, with a Pt outer surface and Ni-rich second atomic layer, Pt(3)Ni(111) is one of the most active surfaces for the ORR (ref. 8), owing to a shift in the d-band centre of the surface Pt atoms that results in a weakened interaction between Pt and intermediate oxide species, freeing more active sites for O(2) adsorption. However, enhancements due solely to alloy structure and composition may not be sufficient to reduce the mass activity enough to satisfy the requirements for fuel-cell commercialization, especially as the high activity of particular crystal surface facets may not easily translate to polyfaceted particles. Here we show that a tailored geometric and chemical materials architecture can further improve ORR catalysis by demonstrating that a composite nanoporous Ni-Pt alloy impregnated with a hydrophobic, high-oxygen-solubility and protic ionic liquid has extremely high mass activity. The results are consistent with an engineered chemical bias within a catalytically active nanoporous framework that pushes the ORR towards completion.

6-Hydroxydopamine-induced alterations in blood-brain barrier permeability

Vascular inflammation is well known for its ability to compromise the function of the blood--brain barrier (BBB). Whether inflammation on the parenchymal side of the barrier, such as that associated with Parkinson's-like dopamine (DA) neuron lesions, similarly disrupts BBB function, is unknown. We assessed BBB integrity by examining the leakage of FITC-labeled albumin or horseradish peroxidase from the vasculature into parenchyma in animals exposed to the DA neurotoxin 6-hydroxydopamine (6OHDA). Unilateral injections of 6OHDA into the striatum or the medial forebrain bundle produced increased leakage in the ipsilateral substantia nigra and striatum 10 and 34 days following 6OHDA. Microglia were markedly activated and DA neurons were reduced by the lesions. The areas of BBB leakage were associated with increased expression of P-glycoprotein and beta 3-integrin expression suggesting, respectively, a compensatory response to inflammation and possible angiogenesis. Behavioural studies revealed that domperidone, a DA antagonist that normally does not cross the BBB, attenuated apomorphine-induced stereotypic behaviour in animals with 6OHDA lesions. This suggests that drugs which normally have no effect in brain can enter following Parkinson-like lesions. These data suggest that the events associated with DA neuron loss compromise BBB function.

Reliability of self-reported contraceptive use and sexual behaviors among adolescent girls

This study examines two issues relevant to adolescents' self-reported sexual and contraceptive use behaviors: reliability of partner-referent reports versus 3 and 6 month reports, and test-retest reliability of reports completed over a 2 week period. Data are from 196 13 to 18 year old girls recruited into this study while they south reproductive care from health clinics in a metropolitan area. All participants reported having had sexual intercourse during the past 6 months. Twice over a 2 week interval, participants completed the same paper and pencil surveys. The survey presented questions about sexual behavior and contraceptive use using 3 sequential frames of reference: within the past 6 months, within the past 3 months, and by specific sexual partners in the past 6 months. Findings demonstrate that adolescent girls can reliably report sexual behavior and contraceptive use over a 6 month interval. Study findings have implications for future research utilizing adolescents' self-reported sexual and contraceptive use behaviors.

Quantum-classical reentrant relaxation crossover in Dy2Ti2O7 spin ice

We have studied spin relaxation in the spin ice compound Dy2Ti2O7 through measurements of the ac magnetic susceptibility. While the characteristic spin-relaxation time (tau) is thermally activated at high temperatures, it becomes almost temperature independent below T(cross) approximately 13 K. This behavior, combined with nonmonotonic magnetic field dependence of tau, indicates that quantum tunneling dominates the relaxational process below that temperature. As the low-entropy spin ice state develops below T(ice) approximately 4 K, tau increases sharply with decreasing temperature, suggesting the emergence of a collective degree of freedom for which thermal relaxation processes again become important as the spins become strongly correlated.

In vitro investigation of the interaction between nitric oxide and cyclo-oxygenase activity in equine ventral colon smooth muscle

The objective of this study was to determine if a correlation exists between the presence of nitric oxide and prostaglandin release in the equine ventral colon smooth muscle, since this relationship may accentuate the inflammatory process during intestinal injury. Tissue was collected from the ventral colon, cut into muscle strips oriented along the circular, longitudinal and taenial layers, and mounted in a tissue bath system. Samples of the bath fluid were collected before, following electrical field stimulation (EFS), and following EFS in the presence of L-NAME, a nitric oxide synthase inhibitor. Muscle strips were also obtained following systemic administration of a cyclo-oxygnease inhibitor and samples were collected using the previously described protocol. Concentrations of prostaglandins were determined in the fluid samples using an ELISA. Electrical field stimulated release of nitric oxide produced a significant increase in prostaglandin production which did not occur in the presence of L-NAME. Systemic administration of flunixin meglumine reduced prostaglandin levels at all sampling periods, although a small increase was present following EFS. The results of this study support the hypothesis that there is a correlation between the release of nitric oxide and the production of prostaglandins in the smooth muscle of the large colon. This association between nitric oxide and prostaglandin may act as an important regulatory mechanism for various physiological mechanisms, such as vascular smooth muscle tone, and may contribute to amplified tissue injury when the induced forms of both enzymes are activated during an inflammatory insult. This suggests that the use and development of COX2 and iNOS inhibitors may help attenuate the inflammatory response following intestinal injury.

Viruses from extreme thermal environments

Viruses of extreme thermophiles are of great interest because they serve as model systems for understanding the biochemistry and molecular biology required for life at high temperatures. In this work, we report the discovery, isolation, and preliminary characterization of viruses and virus-like particles from extreme thermal acidic environments (70-92 degrees C, pH 1.0-4.5) found in Yellowstone National Park. Six unique particle morphologies were found in Sulfolobus enrichment cultures. Three of the particle morphologies are similar to viruses previously isolated from Sulfolobus species from Iceland and/or Japan. Sequence analysis of their viral genomes suggests that they are related to the Icelandic and Japanese isolates. In addition, three virus particle morphologies that had not been previously observed from thermal environments were found. These viruses appear to be completely novel in nature.