Cefadroxil and cephalexin pharmacokinetics and pharmacodynamics in children with musculoskeletal infections.

Cephalexin, a first-generation cephalosporin, is the first-line oral therapy for children with musculoskeletal infections due to methicillin-susceptible Staphylococcus aureus (MSSA). Cefadroxil, a similar first-generation cephalosporin, is an attractive alternative to cephalexin given its longer half-life. In this study, we describe the comparative pharmacokinetics (PK) and pharmacodynamics (PD) of cephalexin and cefadroxil in children with musculoskeletal infections. Children aged 6 months to 18 years with a musculoskeletal infection were enrolled in a prospective, open-label, crossover PK study and given single oral doses of cefadroxil (50-75 mg/kg up to 2,000 mg) and cephalexin (50 mg/kg up to 1,375 mg). Population PK models were developed and used for dosing simulations. Our primary PD target was the achievement of free antibiotic concentrations above the minimum inhibitory concentration (fT >MIC) for 40% of the day for MICs ≤ 4 mg/L. PK of cephalexin (n = 15) and cefadroxil (n = 14) were best described using a one-compartment, first-order absorption model, with a lag time component for cefadroxil. PK parameters were notable for cefadroxil's longer half-life (1.61 h) than cephalexin's (1.10 h). For pediatric weight bands, our primary PD target was achieved by cephalexin 25 mg/kg/dose, maximum 750 mg/dose, administered three times daily and cefadroxil 40 mg/kg/dose, maximum 1,500 mg/dose, administered twice daily. More aggressive dosing was required to achieve higher PD targets. Among children with musculoskeletal infections, oral cephalexin and cefadroxil achieved PD targets for efficacy against MSSA. Given less frequent dosing, twice-daily cefadroxil should be further considered as an alternative to cephalexin for oral step-down therapy for serious infections due to MSSA.

Incretin-Based Weight Loss Pharmacotherapy: Can Resistance Exercise Optimize Changes in Body Composition?

This narrative review highlights the degree to which new antiobesity medications based on gut-derived nutrient-stimulated hormones (incretins) cause loss of lean mass, and the importance of resistance exercise to preserve muscle. Glucagon-like peptide 1 receptor agonists (GLP-1RA) induce substantial weight loss in randomized trials, effects that may be enhanced in combination with glucose-dependent insulinotropic polypeptide (GIP) receptor agonists. Liraglutide and semaglutide (GLP-1RA), tirzepatide (GLP-1 and GIP receptor dual agonist), and retatrutide (GLP-1, GIP, and glucagon receptor triple agonist) are peptides with incretin agonist activity that induce ∼15-24% weight loss in adults with overweight and obesity, alongside beneficial impacts on blood pressure, cholesterol, blood glucose, and insulin. However, these agents also cause rapid and significant loss of lean mass (∼10% or ∼6 kg), comparable to a decade or more of aging. Maintaining muscle mass and function as humans age is crucial to avoiding sarcopenia and frailty, which are strongly linked to morbidity and mortality. Studies indicate that supervised resistance exercise training interventions with a duration >10 weeks can elicit large increases in lean mass (∼3 kg) and strength (∼25%) in men and women. After a low-calorie diet, combining aerobic exercise with liraglutide improved weight loss maintenance compared with either alone. Retaining lean mass during incretin therapy could blunt body weight (and fat) regain on cessation of weight loss pharmacotherapy. We propose that tailored resistance exercise training be recommended as an adjunct to incretin therapy to optimize changes in body composition by preserving lean mass while achieving fat loss.

Impact of Water- and Land-Based Exercise Training on Risk Factors and Vascular Function in Middle-Aged and Older Men and Women.

INTRODUCTION: Exercise improves vascular function, but it is unclear whether benefits are mediated by traditional cardiovascular risk factors or whether sex differences in training effects exist in older adults. We hypothesized that exercise would improve cardiovascular risk factors, that males and females would benefit similarly, and that improvements in risk factors would correlate with changes in vascular function. METHODS: Seventy-two healthy middle-aged/older adults (age, 62 ± 7 yr; 26%♂) were randomized to a land-walking ( n = 23), water-walking ( n = 25), or a nonexercise control group (C; n = 23). The exercise groups undertook supervised and monitored training three times a week for 50 min per session, across 24 wk. Blood pressure, body composition (dual x-ray absorptiometry), blood lipids and glucose, and flow-mediated brachial artery dilation were assessed in all participants at weeks 0 and 24. To maximize power for sex differences and correlation analyses, we pooled the training groups (land-walking + water-walking). RESULTS: Training prevented increases in LDL and total cholesterol/HDL ratio observed in the nonexercise control group. No group by time interactions were observed for other risk factors. Sex differences in training effects existed for visceral fat (-187 ± 189 g♂ vs -15 ± 161 g♀; P = 0.006) and lean mass (-352 ± 1045 g♂ vs 601 ± 1178 g♀; P = 0.008). Improvement in flow-mediated brachial artery dilation was correlated with decreased waist girth ( r = -0.450, P = 0.036), but not with other risk factors. CONCLUSIONS: Exercise training prevented deterioration in lipid levels, whereas sex differences existed for body composition changes with training. Improvement in vascular function was not dependent on changes in risk factors in middle-aged/older adults, suggesting that artery health may be dependent on other exercise-related stimuli.

Relationship between TV Watching during Childhood and Adolescence, and Artery Function in Adulthood.

PURPOSE: Artery dysfunction is an early, integral stage in atherogenesis that predicts future cardiovascular events. Sedentary behavior, such as TV watching, is highly prevalent and associated with increased risk of developing cardiovascular diseases. This study investigated whether patterns of TV watching throughout childhood and adolescence were associated with artery function in adulthood. METHODS: TV watching data were collected when participants of the Raine Study were aged 5, 8, 10, 14, 17, and 20 yr. Previous latent class analysis indicated three trajectory groups of TV watching: low TV (<14 h·wk -1 ), high TV (>14 h·wk -1 ), and increasing TV (change from low TV to high TV). At age 28 yr, participants were invited to undergo tests of brachial and femoral artery function by flow-mediated dilation (FMD). General linear models examined differences in artery function between TV trajectory groups for men and women. RESULTS: Five hundred sixty participants (n = 261 women, n = 299 men) were included in the study. In women, the low TV group had significantly greater femoral artery FMD (10.8 ± 1.6%) than both High TV (9.0 ± 1.3%, P = 0.005) and Increasing TV groups (8.5 ± 1.3%, P < 0.001); these results were maintained following mediation analysis, including contemporaneous risk factors. There were no significant differences in femoral artery FMD between TV trajectory groups in men ( P = 0.955). CONCLUSIONS: This study suggests that TV watching behaviors during childhood and adolescence may have legacy impacts on artery function at age 28 yr, particularly in women. This may increase the risk of atherosclerotic vascular pathologies in later life.

Regional perspectives on the coordination and delivery of paediatric end-of-life care in the UK: a qualitative study.

BACKGROUND: Provision of and access to paediatric end-of-life care is inequitable, but previous research on this area has focused on perspectives of health professionals in specific settings or children with specific conditions. This qualitative study aimed to explore regional perspectives of the successes, and challenges to the equitable coordination and delivery of end-of-life care for children in the UK. The study provides an overarching perspective on the challenges of delivering and coordinating end-of-life care for children in the UK, and the impact of these on health professionals and organisations. Previous research has not highlighted the successes in the sector, such as the formal and informal coordination of care between different services and sectors. METHODS: Semi-structured interviews with Chairs of the regional Palliative Care Networks across the UK. Chairs or co-Chairs (n = 19) of 15/16 Networks were interviewed between October-December 2021. Data were analysed using thematic analysis. RESULTS: Three main themes were identified: one standalone theme ("Communication during end-of-life care"); and two overarching themes ("Getting end-of-life services and staff in the right place", with two themes: "Access to, and staffing of end-of-life care" and "Inconsistent and insufficient funding for end-of-life care services"; and "Linking up healthcare provision", with three sub-themes: "Coordination successes", "Role of the networks", and "Coordination challenges"). Good end-of-life care was facilitated through collaborative and network approaches to service provision, and effective communication with families. The implementation of 24/7 advice lines and the formalisation of joint-working arrangements were highlighted as a way to address the current challenges in the specialism. CONCLUSIONS: Findings demonstrate how informal and formal relationships between organisations and individuals, enabled early communication with families, and collaborative working with specialist services. Formalising these could increase knowledge and awareness of end of life care, improve staff confidence, and overall improve professionals' experiences of delivering care, and families' experiences of receiving it. There are considerable positives that come from collaborative working between different organisations and sectors, and care could be improved if these approaches are funded and formalised. There needs to be consistent funding for paediatric palliative care and there is a clear need for education and training to improve staff knowledge and confidence.

Consultant-led UK paediatric palliative care services: professional configuration, services, funding.

OBJECTIVES: To systematically gather information on the professional team members, services provided, funding sources and population served for all consultant-led specialised paediatric palliative care (SPPC) teams in the UK. METHODS: Two-part online survey. RESULTS: Survey 1: All 17 medical leads from hospital-based or hospice-based SPPC teams responded to the survey (100% response rate).Only six services met the NICE guidance for minimum SPPC team.All services reported providing symptom management, specialist nursing care, end-of-life planning and care, and supporting discharges and transfers to home or hospice for the child's final days-hours. Most services also provided care coordination (n=14), bereavement support (n=13), clinical psychology (n=10) and social work-welfare support (n=9). Thirteen had one or more posts partially or fully funded by a charity.Survey 2: Nine finance leads provided detailed resource/funding information, finding a range of statutory and charity funding sources. Only one of the National Health Service (NHS)-based services fully funded by the NHS. CONCLUSIONS: One-third of services met the minimum criteria of professional team as defined by NICE. Most services relied on charity funding to fund part or all of one professional post and only one NHS-based service received all its funding directly from the NHS.

Time for a Change: Considering Vancomycin Alternatives for Pediatric Methicillin-Resistant Staphylococcus aureus Bacteremia.

Vancomycin remains the standard of care for treating methicillin-resistant Staphylococcus aureus (MRSA) bacteremia in pediatrics largely because no alternative antibiotic is definitively superior. Long-standing historical precedent and S. aureus' notable lack of vancomycin resistance are clear benefits, but vancomycin's use remains plagued by nephrotoxicity and the need for therapeutic drug monitoring, with inadequate consensus on how best to dose or monitor vancomycin in pediatrics. Daptomycin, ceftaroline, and linezolid are all promising alternatives, with improved safety relative to vancomycin. However, inadequate and variable efficacy data limit confidence in their use. Despite this, we contend that it is time for clinicians to reconsider vancomycin's place in clinical use. In this review, we summarize the supporting data for using vancomycin versus these other anti-MRSA antibiotics, present a framework for antibiotic decision-making that considers patient-specific factors, and discuss approaches to antibiotic selection for various etiologies of MRSA bacteremia. This review aims to help pediatric clinicians choose among the various treatment options for MRSA bacteremia, acknowledging that the optimal antibiotic choice is sometimes uncertain.

Exercise and Artery Function in Twins: Sex Differences in a Cross-Over Trial.

BACKGROUND: Physical activity reduces cardiovascular risk, partly via direct effects on the arterial wall. We hypothesized that vascular function responses would be modality-specific, sex-dependent, and express a high degree of heritability. METHODS: We recruited 90 same-sex twins (31 monozygotic, 14 dizygotic dizygotic pairs; 25.8±6.0 years) and randomized 70 (25 monozygotic, 10 dizygotic) to complete, as pairs, 3 months each of resistance and endurance training, separated by a 3-month washout. RESULTS: Brachial artery flow-mediated (FMD%) and glyceryl-trinitrate induced dilation (GTN%) both increased following endurance (FMD%: ∆1.46%, P<0.001; GTN%: ∆1.76%, P=0.004) and resistance (FMD%: ∆1.73%, P<0.001; GTN%: ∆1.68%, P=0.045). About one-third of participants failed to respond to one or other mode; 10% failed to respond to both for FMD% (17% for GTN%). FMD% and GTN% increased significantly in response to both resistance and endurance in females (P<0.05), but not males. Twin analysis revealed that responses to both FMD% and GTN% with exercise training for both modalities were dependent on factors shared by monozygotic pairs and that a large contribution from genetic effects is unlikely. CONCLUSIONS: Our findings indicate that both endurance and resistance can enhance vascular function and that responses in females were more marked. Most individuals respond to one or other form of training, with few unresponsive to both; a finding that has implications for optimizing exercise-based approaches for individualized benefit. Focusing on characteristics of exercise prescription may be more important than the impact of distinct candidate genes when considering exercise as a form of vascular medicine. REGISTRATION: URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=371222; Unique identifier: ACTRN 12616001095459.

Relationship between TV watching during childhood and adolescence and fitness in adulthood in the Raine Study cohort.

To investigate: (1) whether TV watching habits throughout childhood and adolescence, a proxy of sedentary behaviour, impacted cardiorespiratory fitness (CRF) in adulthood, and (2) whether any potential impact of TV watching in childhood and adolescence on CRF in adulthood was changed by adult physical activity (PA) levels. A longitudinal study with questionnaire data available regarding TV watching collected at ages 5, 8, 10, 14, 17 and 20 yrs, allowed trajectories of TV watching to be developed. At age 28 yrs, participants completed a V̇O2peak test and the International Physical Activity Questionnaire. General linear models tested for differences in CRF (time to exhaustion TTE and V̇O2peak mL·kg-1·min-1) between TV watching trajectories. The secondary analysis tested the potential effect current PA levels has on the relationship between TV trajectory and fitness. In total, 449 participants [male n = 255 (56.8%), 28.3 ± 0.5 yrs; female n = 194 (43.2%), 28.2 ± 0.4 yrs] were included in the study. Three distinct trajectories of TV watching were identified: High TV, Increasing TV and Low TV. CRF was lowest in the High TV watching trajectory and increased progressively from High to Increasing TV and Increasing to Low TV (all P < .05). Within each of the TV trajectories, those engaging in high levels of current PA had greater CRF than those engaging in low and moderate PA. TV watching in childhood and adolescence negatively impacts upon adult fitness at the age of 28 years. However, this negative impact of historical TV watching on CRF can largely be attenuated by engaging in higher levels of PA in adulthood.

End of life care for infants, children and young people (ENHANCE): Protocol for a mixed methods evaluation of current practice in the United Kingdom [version 1; peer review: 2 approved].

Background: Although child mortality has decreased over the last few decades, around 4,500 infants and children die in the UK every year, many of whom require palliative care. There is, however, little evidence on paediatric end-of-life care services. The current National Institute for Health and Care Excellence (NICE) guidance provides recommendations about what should be offered, but these are based on low quality evidence. The ENHANCE study aims to identify and investigate the different models of existing end-of-life care provision for infants, children, and young people in the UK, including an assessment of the outcomes and experiences for children and parents, and the cost implications to families and healthcare providers. Methods: This mixed methods study will use three linked workstreams and a cross-cutting health economics theme to examine end-of-life care models in three exemplar clinical settings: infant, children and young adult cancer services (PTCs), paediatric intensive care units (PICUs), and neonatal units (NNUs).Workstream 1 (WS1) will survey current practice in each setting and will result in an outline of the different models of care used. WS2 is a qualitative comparison of the experiences of staff, parents and patients across the different models identified. WS3 is a quantitative assessment of the outcomes, resource use and costs across the different models identified. Discussion: Results from this study will contribute to an understanding of how end-of-life care can provide the greatest benefit for children at the end of their lives. It will also allow us to understand the likely benefits of additional funding in end-of-life care in terms of patient outcomes.

Cefadroxil Comparable to Cephalexin: Minimum Inhibitory Concentrations among Methicillin-Susceptible Staphylococcus aureus Isolates from Pediatric Musculoskeletal Infections.

Cephalexin and cefadroxil are oral first-generation cephalosporins used to treat methicillin-susceptible Staphylococcus aureus (MSSA) infections. Despite its shorter half-life, cephalexin is more frequently prescribed, although cefadroxil is an appealing alternative, given its slower clearance and possibility for less frequent dosing. We report comparative MIC distributions for cefadroxil and cephalexin, as well as for oxacillin, cephalothin, ceftaroline, and cefazolin, for 48 unique clinical MSSA isolates from pediatric patients with musculoskeletal infections. Both cefadroxil and cephalexin had MIC50 values of 2 µg/mL and MIC90 values of 4 µg/mL. MIC50s for oxacillin, cephalothin, and ceftaroline were ≤0.25 µg/mL, and cefazolin's MIC50 was 0.5 µg/mL. While cefadroxil and cephalexin MICs are higher than those for other active agents, the distributions of MICs for cefadroxil and cephalexin are statistically equivalent, suggesting similar in vitro MSSA activities. Cefadroxil should be further considered an alternative agent to cephalexin, although additional work is needed to identify the optimal dose and frequency of these antibiotics for the treatment of serious MSSA infections. IMPORTANCE Cephalexin and cefadroxil are oral antibiotics that are used to treat serious infections due to the bacteria MSSA. While cephalexin is used more commonly, cefadroxil is excreted from the body more slowly; this generally allows patients to take cefadroxil less frequently than cephalexin. In this study, we compared the abilities of cefadroxil, cephalexin, and several other representative intravenous antibiotics to inhibit the growth of MSSA in the laboratory. Bacterial samples were obtained from children with bone, joint, and/or muscle infections caused by MSSA. We found that cefadroxil and cephalexin inhibited the growth of MSSA at similar concentrations, suggesting similar antibacterial potencies. The selected intravenous antistaphylococcal antibiotics generally inhibited bacterial growth with lower antibiotic concentrations. Based on these results, cefadroxil should be further considered an alternative oral antibiotic to cephalexin, although future research is needed to identify the optimal dose and frequency of these antibiotics for serious infections.

Tissue Proteome of 2-Hydroxyacyl-CoA Lyase Deficient Mice Reveals Peroxisome Proliferation and Activation of ω-Oxidation.

Peroxisomal fatty acid α-oxidation is an essential pathway for the degradation of ß-carbon methylated fatty acids such as phytanic acid. One enzyme in this pathway is 2-hydroxyacyl CoA lyase (HACL1), which is responsible for the cleavage of 2-hydroxyphytanoyl-CoA into pristanal and formyl-CoA. Hacl1 deficient mice do not present with a severe phenotype, unlike mice deficient in other α-oxidation enzymes such as phytanoyl-CoA hydroxylase deficiency (Refsum disease) in which neuropathy and ataxia are present. Tissues from wild-type and Hacl1-/- mice fed a high phytol diet were obtained for proteomic and lipidomic analysis. There was no phenotype observed in these mice. Liver, brain, and kidney tissues underwent trypsin digestion for untargeted proteomic liquid chromatography-mass spectrometry analysis, while liver tissues also underwent fatty acid hydrolysis, extraction, and derivatisation for fatty acid gas chromatography-mass spectrometry analysis. The liver fatty acid profile demonstrated an accumulation of phytanic and 2-hydroxyphytanic acid in the Hacl1-/- liver and significant decrease in heptadecanoic acid. The liver proteome showed a significant decrease in the abundance of Hacl1 and a significant increase in the abundance of proteins involved in PPAR signalling, peroxisome proliferation, and omega oxidation, particularly Cyp4a10 and Cyp4a14. In addition, the pathway associated with arachidonic acid metabolism was affected; Cyp2c55 was upregulated and Cyp4f14 and Cyp2b9 were downregulated. The kidney proteome revealed fewer significantly upregulated peroxisomal proteins and the brain proteome was not significantly different in Hacl1-/- mice. This study demonstrates the powerful insight brought by proteomic and metabolomic profiling of Hacl1-/- mice in better understanding disease mechanism in fatty acid α-oxidation disorders.

Management of an Immunocompromised Pediatric Patient With Multiple Hospitalizations for Symptomatic COVID-19.

Relapse of infection due to SARS-CoV-2 has been rarely described and there is little guidance regarding the management of such cases in immunocompromised hosts. We present a case of an adolescent female with B-cell acute lymphoblastic leukemia hospitalized multiple times for symptomatic SARS-CoV-2 infection who was safely treated with 2 courses of remdesivir (RDV) and has had no additional readmissions to date. Though additional studies are needed to confirm the safety and efficacy of an additional course of RDV in the setting of relapsed or prolonged severe COVID-19, our observations suggest that a second course of RDV may be considered.

Participation in sport in childhood and adolescence: Implications for adult fitness.

OBJECTIVES: To investigate whether participation in sport during the developmental stages of life is associated with cardiorespiratory fitness (CRF) in adulthood. DESIGN: Observational longitudinal study. METHODS: Participants were Generation 2 of the Raine Study. Questionnaires related to participation in sport were administered at ages 5, 8, 10, 14 and 17 years. These data were used to develop sex-specific trajectories of sports participation: (for males) Consistent Participators, Drop-Outs and Joiners; and (females) Consistent Participators, Non-Participators and Drop-Outs. At age 28.3 ±â€¯0.6 years, participants completed a graded maximal exercise test (i.e. V̇O2peak test). A General Linear Model assessed differences in CRF between trajectories. RESULTS: 402 participants n = 231 (57.5%) male, n = 171 (42.5%) female were included in the study. In males, Consistent Participators (all p < 0.001) and Joiners (p < 0.050) had greater fitness than Drop-Outs. In females, Consistent Participators had greater fitness than Non-Participators (p < 0.050), but there were no significant differences in fitness between Consistent Participators and Drop-Outs (p > 0.050) or Non-Participators and Drop-Outs (p > 0.050). CONCLUSION: Participation in sport during childhood and adolescence is associated with greater fitness in adulthood, compared to individuals who never participate or those that cease participation in adolescence. A simple dichotomous question regarding sports participation over the childhood and adolescent period can be implemented to predict better fitness outcomes in young adulthood. Childhood and adolescence could be an opportune stage in life for parents, schools and governments to facilitate participation in sport and prevent drop out, as it may have an impact on long term risk reduction, with associated health and economic benefits.

Physical Activity and Cardiovascular Fitness During Childhood and Adolescence: Association With Retinal Nerve Fibre Layer Thickness in Young Adulthood.

PRECIS: Higher physical working capacity (PWC) at age 17 was associated with thicker peripapillary retinal nerve fiber layer (pRNFL) at age 20, suggesting a mechanistic link between cardiovascular fitness and neuroretinal integrity. PURPOSE: Physical activity and cardiovascular fitness have been linked with lower odds of developing glaucoma. We tested the hypothesis that early beneficial effects of physical activity and cardiovascular fitness can be observed by measuring the pRNFL thickness in young healthy adults. METHODS: The Raine Study is a longitudinal study that has followed a cohort since before their births in 1989-1992. Parent-reported physical activity was collected between 8 and 17 years, and latent class analysis was used to identify the participants' physical activity trajectories. At the 20-year follow-up (participants' mean age=20.1±0.4 y), participants' metabolic equivalent of task-minutes/week was determined using self-reported physical activity data. Participants' PWC was assessed at the 14- and 17-year follow-ups to estimate their level of cardiovascular fitness. An eye examination, which included spectral-domain optical coherence tomography imaging, was conducted at the 20-year follow-up for 1344 participants. RESULTS: Parent-reported or participant-reported physical activity was not associated with pRNFL thickness. However, higher PWC at 17 years was associated with thicker pRNFL globally [by 0.3 µm; 95% confidence interval (CI)=0.2-0.6; P<0.001], superotemporally (by 0.4 µm; 95% CI=0.1-0.7; P=0.013), inferonasally (by 0.7 µm; 95% CI=0.1-0.9; P=0.002), and nasally (by 0.4 µm; 95% CI=0.1-0.7; P=0.006) per 10 Watt increase in PWC. CONCLUSIONS: The association between estimated cardiovascular fitness and pRNFL thickness suggests there may be overlapping mechanisms for cardiovascular health and retinal ganglion cell integrity. While the effect sizes were small, it is possible that larger effects and clinically significant associations may arise as we follow this cohort of participants through their later adulthood.

An Immune Recovery-Based Revaccination Protocol for Pediatric Hematopoietic Stem Cell Transplant Recipients: Revaccination Outcomes Following Pediatric HSCT.

Following hematopoietic stem cell transplant (HSCT), patients are at increased risk of vaccine-preventable diseases (VPDs) and experience worse outcomes of VPDs compared to immunocompetent patients. Therefore, patients are routinely vaccinated post-HSCT to restore VPD immunity. Published guidelines recommend revaccination based on time post-HSCT, although optimal revaccination timing and the value of using other clinical and laboratory variables to guide revaccination remain unclear. An institutional immune recovery-based protocol to guide timing of revaccination is used at Children's Hospital Colorado. This protocol incorporates time from transplant, time off immunosuppressive therapy and intravenous immunoglobulin replacement, absence of active graft-versus-host disease (GVHD), and minimum absolute CD4 count, absolute lymphocyte count (ALC), and immunoglobulin G (IgG) levels. The objective of this study is to evaluate the performance of this immune recovery-based revaccination protocol by determining rates of seroprotective vaccine responses achieved and describing demographic, clinical, and laboratory markers associated with protective antibody titers post-revaccination. Rates of seroprotection following revaccination were retrospectively determined for patients who received autologous or allogeneic HSCTs at Children's Hospital Colorado from 2007 to 2017. Percent seropositivity after revaccination was determined for ten VPDs: measles, mumps, rubella, varicella, tetanus, diphtheria, Haemophilus influenzae type B (Hib), poliovirus, hepatitis B virus (HBV), and Streptococcus pneumoniae. The impact of covariates, including post-HSCT vaccine timing, patient demographics, clinical features (diagnosis, donor and conditioning regimen data, GVHD, cytomegalovirus disease), and laboratory parameters (CD4 count, ALC, IgG level), on rates of seroprotection post-revaccination was determined using Wilcoxon rank sum, Fisher's exact, or chi-square tests, as appropriate. One hundred-twelve unique patients among 427 HSCT recipients had available data for both revaccination timing and vaccine titers. Among these, high rates of seroprotection were achieved after revaccination for rubella (100%), diphtheria (100%), tetanus (100%), and Hib (98%). More modest rates of seroprotection were achieved after revaccination with HBV (87%) and pneumococcal conjugate (85%) vaccines. Seroprotection was lower after revaccination with measles (76%), pneumococcal polysaccharide (72%), mumps (67%), and varicella (25%) vaccines. Greater rates of seroprotection were associated with younger age (hepatitis B vaccine, P = .04), lack of prior rituximab treatment (pneumococcal conjugate vaccine, P = .005), lack of total body irradiation (pneumococcal conjugate vaccine, P = .03), and receipt of a non-cord blood transplant (pneumococcal polysaccharide vaccine, P = .04). These results suggest that a revaccination protocol that incorporates both time post-HSCT and patient-specific indicators of immunologic recovery can achieve high rates of seroprotection against most VPDs. Seroprotection rates for HBV and PCV were notably among the highest reported in children post-HSCT, suggesting that an immune recovery-based protocol may improve seroprotection for some VPDs that frequently are associated with lower vaccine responses post-HSCT. Seroprotection rates for other VPDs remained suboptimal after revaccination. Therefore, evaluation of additional strategies, such as the use of novel markers of immune competence and new vaccines, to further optimize protection against VPDs in this population is warranted.

Impact of Antimicrobial Stewardship Bundle on Inpatient Use of Highly Bioavailable Antibacterials.

OBJECTIVES: Intravenous (IV) to enteral transition of highly bioavailable antibacterial drugs is associated with improved safety and lower cost. We evaluated the impact of a bundle of stewardship-driven interventions (including in-person stewardship rounding, clinical pathways, and clinical pharmacist-driven enteral transition workflows) on IV versus enteral administration of highly bioavailable antibacterials at a freestanding children's hospital. METHODS: We collected 2010-2018 inpatient usage data for clindamycin, levofloxacin, ciprofloxacin, metronidazole, rifampin, linezolid, and trimethoprim-sulfamethoxazole. We analyzed total use (in days of therapy [DOTs] per 1000 patient-days [PDs]) and the percentage of total use administered enterally, both hospital wide and stratified by unit subgrouping, specifically comparing use 1-year prestewardship implementation with year-5 postimplementation. RESULTS: Across the 8-year study window, clindamycin, fluoroquinolones, and metronidazole, together, accounted for 96% of IV DOTs for highly bioavailable antibacterials. Overall, clindamycin use decreased from 44.4 to 20.2 DOTs per 1000 PDs (P < .001), with the enteral percentage of total use increasing from 23% to 43% (P < .001) hospital wide. Overall, fluoroquinolone use decreased from 33.7 to 19.3 DOTs per 1000 PDs (P < .001), with the enteral percentage increasing from 40.7% to 55.9% (P < .001). Overall, metronidazole use increased, and the enteral percentage decreased (42.0% to 33.7%; P = .007). Low-IV-use antibacterials (rifampin, linezolid, and trimethoprim-sulfamethoxazole) showed no significant changes in total use or the enteral percentage of total use. CONCLUSIONS: Stewardship interventions were associated with decreased overall use and an increased enteral percentage of total use for both clindamycin and fluoroquinolones, although not metronidazole. These data provide an easy-to-collect benchmark for pediatric hospitals to compare IV with enteral use of highly bioavailable antibacterials within the context of overall antibacterial use.

Effects of Land versus Water Walking Interventions on Vascular Function in Older Adults.

PURPOSE: Endothelial dysfunction is an early and integral atherogenic event. Interventions that improve endothelial function also reduce cardiovascular risk. Due largely to the direct hemodynamic effects of repetitive exercise on the artery wall, exercise training has shown to enhance endothelial function. Land walking (LW) and water walking (WW) induce distinct hemodynamic responses, so the comparison of their effects provides an approach to study shear stress effects on endothelial function. We hypothesized that LW and WW training would have different effects on peripheral artery endothelial function. METHODS: Fifty-one sedentary, older (age = 61.9 ± 6.6 yr, 23.5% male) individuals were randomized into one of three groups: control (n = 16), or one of two exercise groups consisting of 3 × 50 min supervised and individually tailored walking sessions per week for 24 consecutive weeks, performed either on LW (n = 17) or on WW (n = 18). Brachial artery endothelial function (flow-mediated dilation) and smooth muscle cell function (glyceryl trinitrate administration) were tested in all participants before (week 0) and after (week 24) the intervention. RESULTS: Differences were apparent in flow-mediated dilation change between the LW group (week 0, 5.39% ± 0.71%, to week 24, 7.77% ± 0.78%; P = 0.009) and the control group (week 0, 5.87% ± 0.73%, to week 24, 5.78% ± 0.78%). No differences in artery dilation response were found after glyceryl trinitrate administration (all P > 0.05). CONCLUSION: This study suggests that 6-month center-based LW may be superior to WW in terms of improvement in arterial endothelial function in older sedentary individuals.

Visualizing and quantifying cutaneous microvascular reactivity in humans by use of optical coherence tomography: impaired dilator function in diabetes.

The pathophysiology and time course of impairment in cutaneous microcirculatory function and structure remain poorly understood in people with diabetes, partly due to the lack of investigational tools capable of directly imaging and quantifying the microvasculature in vivo. We applied a new optical coherence tomography (OCT) technique, at rest and during reactive hyperemia (RH), to assess the skin microvasculature in people with diabetes with foot ulcers (DFU, n = 13), those with diabetes without ulcers (DNU, n = 9), and matched healthy controls (CON, n = 13). OCT images were obtained from the dorsal part of the foot at rest and following 5 min of local ischemia induced by inflating a cuff around the thigh at suprasystolic level (220 mmHg). One-way ANOVA was used to compare the OCT-derived parameters (diameter, speed, flow rate, and density) at rest and in response to RH, with repeated-measures two-way ANOVA performed to analyze main and interaction effects between groups. Data are means ± SD. At rest, microvascular diameter in the DFU (84.89 ± 14.84 µm) group was higher than CON (71.25 ± 7.6 µm, P = 0.012) and DNU (71.33 ± 12.04 µm, P = 0.019) group. Speed in DFU (65.56 ± 4.80 µm/s, P = 0.002) and DNU (63.22 ± 4.35 µm/s, P = 0.050) were higher than CON (59.58 ± 3.02 µm/s). Microvascular density in DFU (22.23 ± 13.8%) was higher than in CON (9.83 ± 2.94%, P = 0.008), but not than in the DNU group (14.8 ± 10.98%, P = 0.119). All OCT-derived parameters were significantly increased in response to RH in the CON group (all P < 0.01) and DNU group (all P < 0.05). Significant increase in the DFU group was observed in speed (P = 0.031) and density (P = 0.018). The change in density was lowest in the DFU group (44 ± 34.1%) compared with CON (199.2 ± 117.5%, P = 0.005) and DNU (148.1 ± 98.4, P = 0.054). This study proves that noninvasive OCT microvascular imaging is feasible in people with diabetes, provides powerful new physiological insights, and can distinguish between healthy individuals and patients with diabetes with distinct disease severity.