A scoping review shows that no single existing risk of bias assessment tool considers all sources of bias for cross-sectional studies.

OBJECTIVES: Different tools to assess the potential risk of bias (RoB) for cross-sectional studies have been developed, but it is unclear whether all pertinent bias concepts are addressed. We aimed to identify RoB concepts applicable to cross-sectional research validity and to explore coverage for each in existing appraisal tools. STUDY DESIGN AND SETTING: This scoping review followed the Joanna Briggs Institute methodology. We included records of any study design describing or reporting methods, concepts or tools used to consider RoB in health research reported to be descriptive/prevalence survey or analytic/association (cross-sectional) study designs. Synthesis included quantitative and qualitative analysis. RESULTS: Of the 4556 records screened, 90 were selected for inclusion; 67 (74%) described the development of, or validation process for, appraisal tools, 15 (17%) described methodological content or theory relevant to RoB for cross-sectional studies and 8 (9%) records of methodological systematic reviews. Review of methodological reports identified important RoB concepts for both descriptive/prevalence and analytic/association studies. Tools identified (n = 64 unique tools) were either intended to appraise quality or assess RoB in multiple study designs including cross-sectional studies (n = 21; 33%) or cross-sectional designs alone (n = 43; 67%). Several existing tools were modified (n = 17; 27%) for application to cross-sectional studies. The RoB items most frequently addressed in the RoB tools were validity and reliability of the exposure (53%) or outcome (65%) measurement and representativeness of the study population (59%). Most tools did not consider nonresponse or missingness appropriately or at all. CONCLUSION: Assessing cross-sectional studies involve unique RoB considerations. We identified RoB tools designed for broad applicability across various study designs as well as those specifically tailored for cross-sectional studies. However, none of the identified tools comprehensively address all potential biases pertinent to cross-sectional studies. Our findings indicate a need for continued improvement of RoB tools and suggest that the development of context-specific or more precise tools for this study design may be necessary.

Manhattan Vision Screening and Follow-up Study (NYC-SIGHT): a nested cross-sectional assessment of falls risk within a cluster randomised trial.

BACKGROUND: To investigate the feasibility of using the Stopping Elderly Accidents, Deaths and Injuries (STEADI) Falls Risk Tool Kit during community-based eye health screenings to assess falls risk of participants enrolled in the Manhattan Vision Screening and Follow-Up Study (NYC-SIGHT). METHODS: Cross-sectional analysis of data from a 5-year prospective, cluster-randomised clinical trial conducted in affordable housing developments in New York City in adults age 40 years and older. Prescreening questions determined whether participants were at risk of falling. STEADI tests classified participants at low, moderate or high risk of falling. Multivariate logistic regression determined odds of falls risk of all enrolled participants. RESULTS: 708 participants completed the eye health screening; 351 (49.6%) performed STEADI tests; mean age: 71.0 years (SD±11.3); 72.1% female; 53.6% Black, non-Hispanic, 37.6% Hispanic/Latino. Level of falls risk: 32 (9.1%) low, 188 (53.6%) moderate and 131 (37.3%) high. Individuals age >80 (OR 5.921, 95% CI (2.383 to 14.708), p=0.000), had blurry vision (OR 1.978, 95% CI (1.186 to 3.300), p=0.009), high blood pressure (OR 2.131, 95% CI (1.252 to 3.628), p=0.005), arthritis (OR 2.29876, 95% CI (1.362 to 3.875), p=0.002) or foot problems (OR 5.239, 95% CI (2.947 to 9.314), p=0.000) had significantly higher odds of falling, emergency department visits or hospitalisation due to falling. CONCLUSION: This study detected a significant amount of falls risk in an underserved population. The STEADI Falls Risk screening questions were easy for eye care providers to ask, were highly predictive of falls risk and may be adequate for referral to occupational health and/or physical therapy.

Assessment of nursing faculty retirement projections.

BACKGROUND: Nursing faculty retirement is a critical factor contributing to the nursing faculty shortage. PURPOSE: To assess the accuracy of projections on 2016 to 2025 nursing faculty retirements made in a previous study by Fang and Kesten (2017). METHODS: The 2016 to 2022 full-time nursing faculty data collected by American Association of Colleges of Nursing were used to examine the accuracy of the retirement projections for the same years. DISCUSSION: The study found that the mean age of full-time nursing faculty decreased for the first time; the number of faculty retirees and their age distributions projected by Fang and Kesten (2017) were accurate; there was a larger loss of nursing faculty at senior ranks to retirements than was anticipated; nursing faculty aged 50 to 59 in 2015 have made significant progress in doctoral attainment, senior rank, and graduate-level teaching by 2022, but they were still underrepresented in senior ranks compared to the 2016 to 2022 retirees; and for nursing faculty with a PhD degree, their growth was slower than their loss to retirements. CONCLUSION: The findings demonstrate the usefulness of the specific methods for faculty retirement projections. The decline in the mean age of nursing faculty is a positive sign that there is an increased recruitment of younger nurses into academia. The increase in the number of younger nurses entering academia with Doctor of Nursing Practice (DNP)-degree preparation can be leveraged through PhD-DNP collaboration to prepare practice-ready nursing graduates who contribute to health care improvements. Nursing schools need to implement innovative strategies to mentor younger faculty for their successful succession.

Postoperative outcomes and costs of laparoscopic versus robotic distal pancreatectomy: a propensity-matched analysis.

BACKGROUND: Minimally invasive distal pancreatectomy (MIDP) has established advantages over the open approach. The costs associated with robotic DP (RDP) versus laparoscopic DP (LDP) make the robotic approach controversial. We sought to compare outcomes and cost of LDP and RDP using propensity matching analysis at our institution. METHODS: Patients undergoing LDP or RDP between 2000 and 2021 were retrospectively identified. Patients were optimally matched using age, gender, American Society of Anesthesiologists status, body mass index, and tumor size. Between-group differences were analyzed using the Wilcoxon signed-rank test for continuous data, and the McNemar's test for categorical data. Outcomes included operative duration, conversion to open surgery, postoperative length of stay, pancreatic fistula rate, pseudocyst requiring intervention, and costs. RESULTS: 298 patients underwent MIDP, 180 (60%) were laparoscopic and 118 (40%) were robotic. All RDPs were matched 1:1 to a laparoscopic case with absolute standardized mean differences for all matching covariates below 0.10, except for tumor type (0.16). RDP had longer operative times (268 vs 178 min, p < 0.01), shorter length of stay (2 vs 4 days, p < 0.01), fewer biochemical pancreatic leaks (11.9% vs 34.7%, p < 0.01), and fewer interventional radiological drainage (0% vs 5.9%, p = 0.01). The number of pancreatic fistulas (11.9% vs 5.1%, p = 0.12), collections requiring antibiotics or intervention (11.9% vs 5.1%, p = 0.12), and conversion rates (3.4% vs 5.1%, p = 0.72) were comparable between the two groups. The total direct index admission costs for RDP were 1.01 times higher than for LDP for FY16-19 (p = 0.372), and 1.33 times higher for FY20-22 (p = 0.031). CONCLUSIONS: Although RDP required longer operative times than LDP, postoperative stays were shorter. The procedure cost of RDP was modestly more expensive than LDP, though this was partially offset by reduced hospital stay and reintervention rate.

Is Blepharoplasty Cost-effective? Utility Analysis of Dermatochalasis and Cost-effectiveness Analysis of Upper Eyelid Blepharoplasty.

PURPOSE: This cross-sectional prospective study measured utility values of upper eyelid dermatochalasis to quantify its impact on quality of life and assess cost-effectiveness of upper blepharoplasty. METHODS: Utility of dermatochalasis was assessed using the standard reference gamble and time trade-off methods, with dual anchor points of perfect eye function and perfect health. The utility value obtained was used to create a Markov model and run a cost-effectiveness analysis of blepharoplasty as a treatment for dermatochalasis while utilizing the societal perspective. RESULTS: One hundred three patients with dermatochalasis recruited from an urban outpatient ophthalmology clinic completed the utility survey. The authors determined utility values for dermatochalasis ranging from 0.74 to 0.92 depending on the measurement method (standard reference gamble/time trade-off) and anchor points. The cost-effectiveness analysis yielded an incremental cost-effectiveness ratio of $3,146 per quality-adjusted life year, well under the conventional willingness-to-pay threshold of $50,000 per quality-adjusted life year. Probabilistic sensitivity analysis with Monte Carlo simulation demonstrated that blepharoplasty would be cost-effective in 88.1% of cases at this willingness-to-pay threshold. CONCLUSIONS: Dermatochalasis has an impact on quality of life that is significantly associated with level of perceived functional impairment. Rising health care costs have underscored the importance of providing value-based treatment to patients, and the results of this study suggest that blepharoplasty is a cost-effective treatment option for symptomatic bilateral upper eyelid dermatochalasis.

Standardization of interstitial lung disease assessment by ultrasound: results from a Delphi process and web-reliability exercise by the OMERACT ultrasound working group.

OBJECTIVES: Over the last years ultrasound has shown to be an important tool for evaluating lung involvement, including interstitial lung disease (ILD) a potentially severe systemic involvement in many rheumatic and musculoskeletal diseases (RMD). Despite the potential sensitivity of the technique the actual use is hampered by the lack of consensual definitions of elementary lesions to be assessed and of the scanning protocol to apply. Within the Outcome Measures in Rheumatology (OMERACT) Ultrasound Working Group we aimed at developing consensus-based definitions for ultrasound detected ILD findings in RMDs and assessing their reliability in dynamic images. METHODS: Based on the results from a systematic literature review, several findings were identified for defining the presence of ILD by ultrasound (i.e., Am-lines, B-lines, pleural cysts and pleural line irregularity). Therefore, a Delphi survey was conducted among 23 experts in sonography to agree on which findings should be included and on their definitions. Subsequently, a web-reliability exercise was performed to test the reliability of the agreed definitions on video-clips, by using kappa statistics. RESULTS: After three rounds of Delphi an agreement >75 % was obtained to include and define B-lines and pleural line irregularity as elementary lesions to assess. The reliability in the web-based exercise, consisting of 80 video-clips (30 for pleural line irregularity, 50 for B-lines), showed moderate inter-reader reliability for both B-lines (kappa = 0.51) and pleural line irregularity (kappa = 0.58), while intra-reader reliability was good for both B-lines (kappa = 0.72) and pleural line irregularity (kappa = 0.75). CONCLUSION: Consensus-based ultrasound definitions for B-lines and pleural line irregularity were obtained, with moderate to good reliability to detect these lesions using video-clips. The next step will be testing the reliability in patients with ILD linked to RMDs and to propose a consensual and standardized protocol to scan such patients.

Association of Psychosocial Factors with Activation Among Patients with Glaucoma.

OBJECTIVE: To investigate the association of psychosocial factors with health self-management behaviors and beliefs among patients with primary open-angle glaucoma (POAG). DESIGN: Prospective cross-sectional cohort study. PARTICIPANTS: Patients (n = 202) with mild, moderate, or advanced bilateral POAG. METHODS: Patients (N = 1164) were identified from electronic medical records at a single academic medical center. Letters soliciting participation were mailed to 591 randomly selected potential participants. Psychometric measures and a social determinants of health questionnaire were administered by phone to 202 study participants. MAIN OUTCOME MEASURES: The National Eye Institute Visual Function Questionnaire-8 (NEI-VFQ), the Multidimensional Health Locus of Control (MHLC), the Perceived Medical Condition Self-Management Scale-4, the Patient Health Questionnaire-9 (PHQ), the Patient Activation Measure-13 (PAM), a health literacy question, and a social determinants of health questionnaire. RESULTS: For each increase in level of POAG severity, there was a decrease in mean NEI-VFQ score (P < 0.001). For each unit increase in NEI-VFQ item 1, self-rated vision, mean PAM score increased (R2 = 5.3%; P = 0.001; 95% confidence interval [CI], 0.077-0.276). For each unit increase in "Internal" on the MHLC, mean PAM score increased (R2 = 19.3%; 95% CI, 0.649-1.166; P < 0.001). For each unit increase in "Doctors" on the MHLC, mean PAM score increased (R2 = 11.0%; 95% CI, 1.555-3.606; P < 0.001). For each unit increase in "Chance" on the MHLC, mean PAM score decreased (R2 = 2.6%; 95% CI, -0.664 to -0.051; P = 0.023). On multivariate analysis, adjusting for age, sex and race, for each unit increase in PHQ, mean PAM score decreased (95% CI, 0.061-1.35; P = 0.032); for each unit increase in MHLC "Doctors", mean PAM score increased (95% CI, -1.448 to 3.453; P < 0.001); for each unit increase in MHLC "Internal", mean PAM score increased (95% CI, 0.639-1.137; P < 0.001); for each unit increase in MHLC "Chance", mean PAM score decreased (95% CI, -0.685 to -0.098; P = 0.009). CONCLUSIONS: We identified modifiable behavioral factors that could increase patients' self-perceived ability and confidence to manage their own eye care. Locus of control (MHLC), level of depression (PHQ), and self-rated functional vision (NEI-VFQ) were each associated with patient behaviors, attitudes, and beliefs needed for health self-management (activation, assessed by the PAM) and may be important determinants of adherence behaviors. Targeting change in patients' care beliefs and behaviors may improve activation and treatment outcomes. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Manhattan Vision Screening and Follow-Up Study (NYC-SIGHT): optometric exam improves access and utilization of eye care services.

PURPOSE: To describe the benefits of optometric evaluation for detection of vision-affecting conditions in the context of community-based eye health screenings and identify factors associated with having a recent dilated eye exam. METHODS: Enrolled participants were age 40 and older, living independently in affordable housing developments in New York City. Eye health screening failure and criteria for seeing the on-site study optometrist were defined as visual acuity 20/40 or worse in either eye, intraocular pressure 23-29 mmHg, or an unreadable fundus image. The optometrist conducted a manifest refraction using loose lenses and used a portable slit lamp and ophthalmoscope to perform a non-dilated anterior and posterior segment ocular health evaluation. Demographics, social determinants of health, eye health screening results, and rates of suspected ophthalmic conditions were recorded. To determine factors associated with having a recent dilated eye exam, which was the main outcome for this statistical analysis, a stepwise multivariate logistic regression was performed. RESULTS: A total of 708 participants were screened, 308 attended the optometric exam; mean age 70.7 ± 11.7 [standard deviation (SD)] years. Among this subgroup, 70.1% identified as female, 54.9% self-identified as African American, 39% as Hispanic/Latino, and 26.6% Dominican ethnicity; 78.2% (241/308) had not undergone a dilated eye exam within the last year, 71.4% reported they did not have an eye care provider. Stepwise multivariate logistic regression analysis indicated that participants who self-reported having cataracts (odds ratio (OR) 2.15; 95% confidence interval (CI) 1.03-4.47; p = 0.041), self-reported having glaucoma/glaucoma suspect (OR 5.60; 95% CI 2.02-15.43; p = 0.001), or spoke Spanish as their primary language (OR 3.25; 95% CI 1.48-7.11; p = 0.003) had higher odds of having a recent dilated eye exam. CONCLUSIONS: This community-based screening initiative demonstrated the effectiveness of optometric exams in detecting vision-affecting conditions and identified factors associated with having a recent dilated eye exam. Optometrists play a vital role in increasing access to eye care for high-risk, underserved populations. TRIAL REGISTRATION: ClinicalTrials.gov (NCT04271709).

Operating Room Supply Cost and Value of Care after Implementing a Sustainable Quality Intervention.

BACKGROUND: Variability in operating room supply cost is a modifiable cause of suboptimal resource use and low value of care (outcomes vs cost). This study describes implementation of a quality improvement intervention to decrease operating room supply costs. STUDY DESIGN: An automated electronic health record data pipeline harmonized operating room supply cost data with patient and case characteristics and outcomes. For inpatient procedures, predicted mortality and length of stay were used to calculate observed-to-expected ratios and value of care using validated equations. For commonly performed (1 or more per week) procedures, the pipeline generated figures illustrating individual surgeon performance vs peers, costs for each surgeon performing each case type, and control charts identifying out-of-control cases and surgeons with more than 90th percentile costs, which were shared with surgeons and division chiefs alongside guidance for modifying case-specific supply instructions to operating room nurses and technicians. RESULTS: Preintervention control (1,064 cases for 7 months) and postintervention (307 cases for 2 months) cohorts had similar baseline characteristics across all 16 commonly performed procedures. Median costs per case were lower in the intervention cohort ($811 [$525 to $1,367] vs controls: $1,080 [$603 to $1,574], p < 0.001), as was the incidence of out-of-control cases (19 (6.2%) vs 110 (10.3%), p = 0.03). Duration of surgery, length of stay, discharge disposition, and 30-day mortality and readmission rates were similar between cohorts. Value of care was higher in the intervention cohort (1.1 [0.1 to 1.5] vs 1.0 [0.2 to 1.4], p = 0.04). Pipeline runtime was 16:07. CONCLUSIONS: An automated, sustainable quality improvement intervention was associated with decreased operating room supply costs and increased value of care.

Phantom study for 90Y liver radioembolization dosimetry with a long axial field-of-view PET/CT.

PURPOSE: The physical properties of yttrium-90 (90Y) allow for imaging with positron emission tomography/computed tomography (PET/CT). The increased sensitivity of long axial field-of-view (LAFOV) PET/CT scanners possibly allows to overcome the small branching ratio for positron production from 90Y decays and to improve for the post-treatment dosimetry of 90Y of selective internal radiation therapy. METHODS: For the challenging case of an image quality body phantom, we compare a full Monte Carlo (MC) dose calculation with the results from the two commercial software packages Simplicit90Y and Hermes. The voxel dosimetry module of Hermes relies on the 90Y images taken with a LAFOV PET/CT, while the MC and Simplicit90Y dose calculations are image independent. RESULTS: The resulting doses from the MC calculation and Simplicit90Y agree well within the error margins. The image-based dose calculation with Hermes, however, consistently underestimates the dose. This is due to the mismatch of the activity distribution in the PET images and the size of the volume of interest. We found that only for the smallest phantom sphere there is a statistically significant dependence of the Hermes dose on the image reconstruction parameters and scan time. CONCLUSION: Our study shows that Simplicit90Y's local deposition model can provide a reliable dose estimate. On the other hand, the image based dose calculation suffers from the suboptimal reconstruction of the 90Y distribution in small structures.

A Literary Pediatric Retina Fellowship With Michael T. Trese, MD.

Michael T. Trese, MD (1946-2022), a vitreoretinal surgeon, made significant contributions to the field of retina. Although most known for his work in pediatric retina surgery, he was a pioneer in areas such as medical retina, translational research, and telemedicine. This article reviews his major contributions to spread his knowledge more widely to vitreoretinal trainees and specialists. We discuss six areas where Trese made a lasting impact: lens-sparing vitrectomy, familial exudative vitreoretinopathy, congenital X-linked retinoschisis, autologous plasmin enzyme, regenerative medicine, and telemedicine. [Ophthalmic Surg Lasers Imaging Retina 2023;54:701-712.].

An assessment of factors associated with early postoperative stiffness in arthroscopic rotator cuff repair.

BACKGROUND: Postoperative stiffness affects up to 20% of patients following arthroscopic rotator cuff repair. Recent evidence indicates that early postoperative stiffness may associated with lower retear rates. This study aimed to identify the independent predictors of early postoperative stiffness. METHODS: A retrospective cohort study of 1526 rotator cuff repairs was performed. Range of motion at 6-week postop was used to identify stiff patients. Stiffness was defined as external rotation <27.5o or forward flexion <145o . Multiple logistic regression analysis was used to identify the independent predictors of 6-week stiffness. RESULTS: The independent predictors for external rotation stiffness at 6-week postop were more recent cases (Wald = 60), restricted preoperative external rotation (Wald = 36), younger age (Wald = 21) and poorer surgeon-ranked tissue quality (Wald = 15). The independent predictors for forward flexion stiffness were more recent cases (Wald = 101), restricted preoperative forward flexion (Wald = 16) and external rotation (Wald = 13) and female patients (Wald = 12). All patients that developed early postoperative stiffness had recovered range of motion by 6 months to preoperative levels (P < 0.0001). A significantly greater proportion of younger patients (40-49) developed postoperative stiffness when compared to older patients aged 50-59 (P < 0.0062), 70-79 (P < 0.0126) and 80-89 (P < 0.004). Patients that retore had significantly greater average 6-week postoperative range of motion. CONCLUSIONS: Patients earlier in the study were found to have greater postoperative range of motion, which coincided with a more aggressive rehabilitation program with less immobilization. Thus, the data supports the hypothesis that a temporary period of shoulder stiffness facilitates tendon repair and ultimately a better outcome post rotator cuff repair.

Estimating shadow prices in economies with multiple market failures.

Approaches to the estimation of shadow prices generally assume that all but one market function correctly. However, multiple market failures are common in developing countries. We present a theoretical model and an empirical strategy to estimate the shadow price of a subsistence good in an economy where labor markets fail. Our results show that: 1) among subsistence producers, the shadow price of this good must be greater than or equal to the market price, and equal to it for surplus growers; and 2) current methods create biases when the otherwise-perfect-markets assumption is violated. The propositions are tested using a representative survey for rural Mexico. We find that the shadow wage is below that of the market (MXN $93.2/day vs. MXN $132.3/day), and that the shadow price for subsistence corn is over ten times greater than its market price (MXN $32.37/kg vs. MXN $3.19/kg). Unbiased shadow price estimates for subsistence goods help to overcome the limitations of current income poverty measures: their overestimation of the purchasing power of subsistence households and their underestimation of the value of subsistence goods. In rural Mexico, current practice underestimates the population in food poverty by 2%; an additional 9% has income above the poverty line yet fail to meet the utilization dimension of food security.

Antibacterial Efficacy of Manuka Honey-Doped Chitosan-Gelatin Cryogel and Hydrogel Scaffolds in Reducing Infection.

Honey has been used for centuries to reduce bacterial infection; Manuka honey (MH) possesses an additional antibacterial agent, Unique Manuka Factor (UMF). However, MH's physical properties challenge delivery to the wound site. Tissue-engineered scaffolds (cryogels/hydrogels) provide a potential vehicle for MH delivery, but effects on bacterial clearance and biofilm formation demand further examination. MH (0, 1, 5, or 10%) was incorporated into both chitosan-gelatin (1:4 ratio; 4%) cryogels and hydrogels. To assess physical changes, all scaffolds were imaged with scanning electron microscopy and subjected to swell testing to quantify pore size and rehydration potential, respectively. As MH concentration increased, both pore size and scaffold swelling capacity decreased. Both bacterial clearance and biofilm formation were also assessed, along with cellular infiltration. Bacterial clearance testing with S. aureus demonstrated that MH cryogels are superior to 0% control, indicating the potential to perform well against Gram-positive bacteria. However, higher concentrations of MH resulted in cell death over time. These results support our hypothesis that MH release from 5% cryogels would induce reduced viability for four bacteria species without compromising scaffold properties. These outcomes assist in the development of a standard of practice for incorporating MH into scaffolds and the evaluation of biofilm reduction.

Cardiac PET Myocardial Blood Flow Quantification Assessment of Early Cardiac Allograft Vasculopathy.

BACKGROUND: Positron emission tomography (PET) has demonstrated utility for diagnostic and prognostic assessment of cardiac allograft vasculopathy (CAV) but has not been evaluated in the first year after transplant. OBJECTIVES: The authors sought to evaluate CAV at 1 year by PET myocardial blood flow (MBF) quantification. METHODS: Adults at 2 institutions enrolled between January 2018 and March 2021 underwent prospective 3-month (baseline) and 12-month (follow-up) post-transplant PET, endomyocardial biopsy, and intravascular ultrasound examination. Epicardial CAV was assessed by intravascular ultrasound percent intimal volume (PIV) and microvascular CAV by endomyocardial biopsy. RESULTS: A total of 136 PET studies from 74 patients were analyzed. At 12 months, median PIV increased 5.6% (95% CI: 3.6%-7.1%) with no change in microvascular CAV incidence (baseline: 31% vs follow-up: 38%; P = 0.406) and persistent microvascular disease in 13% of patients. Median capillary density increased 30 capillaries/mm2 (95% CI: -6 to 79 capillaries/mm2). PET myocardial flow reserve (2.5 ± 0.7 vs 2.9 ± 0.8; P = 0.001) and stress MBF (2.7 ± 0.6 vs 2.9 ± 0.6; P = 0.008) increased, and coronary vascular resistance (CVR) (49 ± 13 vs 47 ± 11; P = 0.214) was unchanged. At 12 months, PET and PIV had modest correlation (stress MBF: r = -0.35; CVR: r = 0.33), with lower stress MBF and higher CVR across increasing PIV tertiles (all P < 0.05). Receiver-operating characteristic curves for CAV defined by upper-tertile PIV showed areas under the curve of 0.74 for stress MBF and 0.73 for CVR. CONCLUSIONS: The 1-year post-transplant PET MBF is associated with epicardial CAV, supporting potential use for early noninvasive CAV assessment. (Early Post Transplant Cardiac Allograft Vasculopahty [ECAV]; NCT03217786).

Effects of tissue heterogeneity and comparisons of collapsed cone and Monte Carlo fast neutron patient dosimetry using the University of Washington clinical neutron therapy system (CNTS).

Fast neutron therapy is a high linear energy transfer (LET) radiation treatment modality offering advantages over low LET radiations. Multileaf collimator technology reduces normal-tissue dose (toxicity) and makes neutron therapy more comparable to MV x-ray treatments. Published clinical-trial and other experiences with fast neutron therapy are reported. Early comparative studies failed to consider differences in target-dose spatial conformality between x-ray and neutron treatments, which is especially important for organs-at-risk close to tumor targets. Treatments planning systems (TPS) for high-energy neutrons lag behind TPS tools for MV x-rays, creating challenges for comparative studies of clinical outcomes. A previously published Monte Carlo model of the University of Washington (UW) Clinical Neutron Therapy System (CNTS) is refined and integrated with the RayStation TPS as an external dose planning/verification tool. The collapsed cone (CC) dose calculations in the TPS are based on measured dose profiles and output factors in water, with the absolute dose determined using a tissue-equivalent ionization chamber. For comparison, independent (external) Monte Carlo simulation computes dose on a voxel-by-voxel basis using an atlas that maps Hounsfield Unit (HU) numbers to elemental composition and density. Although the CC algorithm in the TPS accurately computes neutron dose to water compared to Monte Carlo calculations, calculated dose to water differs from bone or tissue depending largely on hydrogen content. Therefore, the elemental composition of tissue and bone, rather than the material or electron density, affects fast neutron dose. While the CC algorithm suffices for reproducible patient dosimetry in fast neutron therapy, adopting methods that consider tissue heterogeneity would enhance patient-specific neutron dose accuracy relative to national standards for other types of ionizing radiation. Corrections for tissue composition have a significant impact on absolute dose and the relative biological effectiveness (RBE) of neutron treatments compared to other radiation types (MV x-rays, protons, and carbon ions).

Prey consumption does not restore hydration state but mitigates the energetic costs of water deprivation in an insectivorous lizard.

To cope with limited availability of drinking water in their environment, terrestrial animals have developed numerous behavioral and physiological strategies including maintaining an optimal hydration state through dietary water intake. Recent studies performed in snakes, which are generalist carnivorous reptiles, suggest that the benefits of dietary water intake are negated by hydric costs of digestion. Most lizards are generalist insectivores that can shift their prey types, but firm experimental demonstration of dietary water intake is currently missing in these organisms. Here, we performed an experimental study in the common lizard Zootoca vivipara, a keystone mesopredator from temperate climates exhibiting a great diversity of prey in its mesic habitats, in order to investigate the effects of food consumption and prey type on physiological responses to water deprivation. Our results indicate that common lizards cannot improve their hydration state through prey consumption, irrespective of prey type, suggesting that they are primarily dependent upon drinking water. Yet, high-quality prey consumption reduced the energetic costs of water deprivation, potentially helping lizards to conserve a better body condition during periods of limited water availability. These findings have important implications for understanding the physiological responses of ectotherms to water stress, and highlight the complex interactions between hydration status, energy metabolism and feeding behavior in insectivorous lizards.