Quantifying Inferior Vena Cava Compliance and Distensibility in an In Vivo Ovine Model Using 3D Angiography.

Synthetic vascular grafts overcome some challenges of allografts, autografts, and xenografts but are often more rigid and less compliant than the native vessel into which they are implanted. Compliance matching with the native vessel is emerging as a key property for graft success. The current gold standard for assessing vessel compliance involves the vessel's excision and ex vivo biaxial mechanical testing. We developed an in vivo method to assess venous compliance and distensibility that better reflects natural physiology and takes into consideration the impact of a pressure change caused by flowing blood and by any morphologic changes present. This method is designed as a survival procedure, facilitating longitudinal studies while potentially reducing the need for animal use. Our method involves injecting a 20 mL/kg saline bolus into the venous vasculature, followed by the acquisition of pre and post bolus 3D angiograms to observe alterations induced by the bolus, concurrently with intravascular pressure measurements in target regions. We are then able to measure the circumference and the cross-sectional area of the vessel pre and post bolus. With these data and the intravascular pressure, we are able to calculate the compliance and distensibility with specific equations. This method was used to compare the inferior vena cava's compliance and distensibility in native unoperated sheep to the conduit of sheep implanted with a long-term expanded polytetrafluorethylene (PTFE) graft. The native vessel was found to be more compliant and distensible than the PTFE graft at all measured locations. We conclude that this method safely provides in vivo measurements of vein compliance and distensibility.

Earlier winter/spring runoff and snowmelt during warmer winters lead to lower summer chlorophyll-a in north temperate lakes.

Winter conditions, such as ice cover and snow accumulation, are changing rapidly at northern latitudes and can have important implications for lake processes. For example, snowmelt in the watershed-a defining feature of lake hydrology because it delivers a large portion of annual nutrient inputs-is becoming earlier. Consequently, earlier and a shorter duration of snowmelt are expected to affect annual phytoplankton biomass. To test this hypothesis, we developed an index of runoff timing based on the date when 50% of cumulative runoff between January 1 and May 31 had occurred. The runoff index was computed using stream discharge for inflows, outflows, or for flows from nearby streams for 41 lakes in Europe and North America. The runoff index was then compared with summer chlorophyll-a (Chl-a) concentration (a proxy for phytoplankton biomass) across 5-53 years for each lake. Earlier runoff generally corresponded to lower summer Chl-a. Furthermore, years with earlier runoff also had lower winter/spring runoff magnitude, more protracted runoff, and earlier ice-out. We examined several lake characteristics that may regulate the strength of the relationship between runoff timing and summer Chl-a concentrations; however, our tested covariates had little effect on the relationship. Date of ice-out was not clearly related to summer Chl-a concentrations. Our results indicate that ongoing changes in winter conditions may have important consequences for summer phytoplankton biomass and production.

A Survey of Music Therapists Working in Pediatric Medical Settings in the United States.

Music therapy is becoming a standard supportive care service in many pediatric hospitals across the United States. However, more detailed information is needed to advance our understanding about current clinical practice and increase availability of pediatric music therapy services. The purpose of this cross-sectional survey study was to collect and summarize data about music therapists working in pediatric medical settings. Specifically, we collected information about (1) therapist demographics, (2) organizational structure, (3) service delivery and clinical practice, and (4) administrative/supervisory responsibilities. Board-certified music therapists working in pediatric medical settings (n = 118) completed a 37-item online questionnaire. We analyzed survey data using descriptive statistics and content analysis. Findings indicated that there is a ratio of approximately one music therapist for every 100 patient beds, that one-third of respondents are the only music therapist in their setting, and that half of the surveyed positions are philanthropically funded. Prioritizing patient referrals based on acuity was common (95.7%, n = 110), with palliative care and pain as the most highly prioritized needs. More than half of respondents reported serving in high acuity areas such as the pediatric intensive care, hematology/oncology, or neonatal intensive care units. We recommend replication of this survey in five years to examine growth and change in service delivery among pediatric music therapists over time, with additional studies to (a) explore how therapist-to-patient ratios influence quality of care, (b) identify factors that contribute to sustainability of programs, and (c) determine how expansion of services support a broader population of patients and families.

De Novo Designed Amphipathic α-Helical Antimicrobial Peptides Incorporating Dab and Dap Residues on the Polar Face To Treat the Gram-Negative Pathogen, Acinetobacter baumannii.

We have designed de novo and synthesized ten 26-residue D-conformation amphipathic α-helical cationic antimicrobial peptides (AMPs), seven with "specificity determinants", which provide specificity for prokaryotic cells over eukaryotic cells. The ten AMPs contain five or six positively charged residues (d-Arg, d-Lys, d-Orn, l-Dab, or l-Dap) on the polar face to understand their role in hemolytic activity against human red blood cells and antimicrobial activity against seven Acinetobacter baumannii strains, resistant to polymyxin B and colistin, and 20 A. baumannii worldwide isolates from 2016 and 2017 with antibiotic resistance to 18 different antibiotics. AMPs with specificity determinants and with l-Dab and l-Dap residues on the polar face have essentially no hemolytic activity at 1000 µg/mL (380 µM), showing for the first time the importance of these unusual amino acid residues in solving long-standing hemolysis issues of AMPs. Specificity determinants maintained excellent antimicrobial activity in the presence of human sera.

Relaxation Training and Postoperative Music Therapy for Adolescents Undergoing Spinal Fusion Surgery.

Spinal fusion for idiopathic scoliosis is one of the most painful surgeries experienced by adolescents. Music therapy, utilizing music-assisted relaxation with controlled breathing and imagery, is a promising intervention for reducing pain and anxiety for these patients. It can be challenging to teach new coping strategies to post-operative patients who are already in pain. This study evaluated the effects of introducing music-assisted relaxation training to adolescents before surgery. Outcome measures were self-reported pain and anxiety, recorded on 0-10 numeric rating scale, and observed behavioral indicators of pain and relaxation. The training intervention was a 12-minute video about music-assisted relaxation with opportunities to practice before surgery. Forty-four participants between the ages of 10 and 19 were enrolled. Participants were randomly assigned to the experimental group that watched the video at the preoperative visit or to the control group that did not watch the video. All subjects received a music therapy session with a board certified music therapist on post-operative day 2 while out of bed for the first time. Pain and anxiety were significantly reduced from immediately pre-therapy to post-therapy (paired t-test; p).

A non-randomized [corrected] controlled trial of the active music engagement (AME) intervention on children with cancer.

BACKGROUND: Coping theorists argue that environmental factors affect how children perceive and respond to stressful events such as cancer. However, few studies have investigated how particular interventions can change coping behaviors. The active music engagement (AME) intervention was designed to counter stressful qualities of the in-patient hospital environment by introducing three forms of environmental support. METHOD: The purpose of this multi-site randomized controlled trial was to determine the efficacy of the AME intervention on three coping-related behaviors (i.e. positive facial affect, active engagement, and initiation). Eighty-three participants, ages 4-7, were randomly assigned to one of three conditions: AME (n = 27), music listening (ML; n = 28), or audio storybooks (ASB; n = 28). Conditions were videotaped to facilitate behavioral data collection using time-sampling procedures. RESULTS: After adjusting for baseline differences, repeated measure analyses indicated that AME participants had a significantly higher frequency of coping-related behaviors compared with ML or ASB. Positive facial affect and active engagement were significantly higher during AME compared with ML and ASB (p<0.0001). Initiation was significantly higher during AME than ASB (p<0.05). CONCLUSION: This study supports the use of the AME intervention to encourage coping-related behaviors in hospitalized children aged 4-7 receiving cancer treatment.