Publications by authors named "Samantha Bacon"

Background: Valganciclovir is the only approved antiviral for cytomegalovirus (CMV) prevention in pediatric solid organ transplantation (SOT). Additional approaches may be needed to improve outcomes.

Methods: A multicenter retrospective study from 2016 to 2019 was conducted of pediatric SOT recipients in whom at least 3 months of valganciclovir prophylaxis was planned.

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Optimal dosing of valganciclovir (VGCV) for cytomegalovirus (CMV) prevention in pediatric solid organ transplantation recipients (SOTR) is controversial. Dosing calculated based on body surface area (BSA) and creatinine clearance is recommended but simplified body weight (BW) dosing is often prescribed. We conducted a retrospective 6-center study to compare safety and efficacy of these strategies in the first-year posttransplant There were 100 (24.

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Objective: This study aimed to phenotype and compare adipose, hepatic, and muscle insulin sensitivity (IS) in a diet- and physical activity-controlled cohort of normoglycemic youth with obesity with that of participants without obesity (controls) to distinguish early metabolic abnormalities in pediatric obesity.

Methods: Thirty-eight participants (17 in the control group [BMI < 85th percentile] and 21 youth with obesity [BMI ≥ 95th percentile]; age: 12-21 years; 76% female; Tanner stage 4-5; sedentary) were enrolled. Tissue-specific IS was measured using a four-phase hyperinsulinemic-euglycemic clamp with glucose and glycerol isotope tracers to assess suppression of endogenous glucose release and lipolysis by insulin.

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Adolescents with type 2 diabetes (T2D) have severe insulin resistance (IR) secondary to obesity, genetics, and puberty, and IR predicts metabolic comorbidities. Adults with T2D have multitissue IR, which has guided therapeutic developments, but this is not established in youth. We sought to assess adipose, hepatic, and peripheral insulin sensitivity in adolescents with and without T2D.

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Context: Adolescents with type 1 diabetes (T1D) have difficulty obtaining optimal glucose control, which may relate to insulin resistance (IR), especially during puberty. Moreover, IR increases the risk for cardiovascular disease, the leading cause of death in T1D. However, the tissue specificity of IR in adolescents with T1D has not been fully phenotyped.

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Objective: Obese girls with polycystic ovarian syndrome (PCOS) have decreased insulin sensitivity (IS), muscle mitochondrial dysfunction and increased liver fat, which may contribute to their increased risk for type 2 diabetes. Less is known regarding normal-weight girls with PCOS.

Methods: Normal-weight girls with PCOS [n =18, age 15.

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Intramuscular triglyceride (IMTG) concentration is elevated in insulin-resistant individuals and was once thought to promote insulin resistance. However, endurance-trained athletes have equivalent concentration of IMTG compared with individuals with type 2 diabetes, and have very low risk of diabetes, termed the "athlete's paradox." We now know that IMTG synthesis is positively related to insulin sensitivity, but the exact mechanisms for this are unclear.

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Objective: Increased liver fat and type 2 diabetes are prevalent in women with polycystic ovarian syndrome (PCOS) and cause excess mortality, yet little is known about their development during adolescence. The objective of this study was to measure hepatic steatosis and related metabolic contributors in girls with obesity, with and without PCOS.

Methods: Nondiabetic adolescents with obesity, 41 with PCOS (PCOS; age 15.

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Several recent reports indicate that the balance of skeletal muscle phosphatidylcholine (PC) and phosphatidylethanolamine (PE) is a key determinant of muscle contractile function and metabolism. The purpose of this study was to determine relationships between skeletal muscle PC, PE and insulin sensitivity, and whether PC and PE are dynamically regulated in response to acute exercise in humans. Insulin sensitivity was measured via intravenous glucose tolerance in sedentary obese adults (OB; n = 14), individuals with type 2 diabetes (T2D; n = 15), and endurance-trained athletes (ATH; n = 15).

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Aims/hypotheses: Ceramides and other sphingolipids comprise a family of lipid molecules that accumulate in skeletal muscle and promote insulin resistance. Chronic endurance exercise training decreases muscle ceramides and other sphingolipids, but less is known about the effects of a single bout of exercise.

Methods: We measured basal relationships and the effect of acute exercise (1.

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Ceramides and sphingolipids are a family of lipid molecules that circulate in serum and accumulate in skeletal muscle, promoting insulin resistance. Plasma ceramide and dihydroceramide are related to insulin resistance, yet less is known regarding other ceramide and sphingolipid species. Despite its association with insulin sensitivity, chronic endurance exercise training does not change plasma ceramide and sphingolipid content, with little known regarding a single bout of exercise.

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Background: This study presents results from qualitative interviews conducted with participants in a study on the effectiveness of the Location-Based Monitoring and Intervention System for Alcohol Use Disorders (LBMI-A), a smartphone-based, stand-alone intervention application (app) for adults with alcohol use disorders.

Materials And Methods: Participants were provided an LBMI-A-enabled smartphone to use during a 6-week pilot study. The LBMI-A was composed of psychoeducational modules, assessment and feedback of alcohol use patterns, geographic high-risk location monitoring and alerts, and in vivo assessment and intervention for alcohol cravings and help with managing psychological distress.

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Objective: Abnormal endogenous glucose production (EGP) is a characteristic feature in people with impaired fasting glucose (IFG). We sought to determine whether impaired hepatic glucose sensing contributes to abnormal EGP in IFG and whether it could be experimentally restored.

Methods: Glucose production (rate of appearance; Ra) and flux (glucose cycling) were assessed during a hyperglycemic-euinsulinemic somatostatin clamp with an infusion of [6,6-(2)H2-]glucose and [2-(2)H]glucose before and after enhanced hepatic glucokinase activity via an infusion of low-dose fructose in people with IFG and normal glucose tolerance (NGT).

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Advances in mobile technology provide an opportunity to deliver in-the-moment interventions to individuals with alcohol use disorders, yet availability of effective "apps" that deliver evidence-based interventions is scarce. We developed an immediately available, portable, smartphone-based intervention system whose purpose is to provide stand-alone, self-administered assessment and intervention. In this paper, we describe how theory and empirical evidence, combined with smartphone functionality contributed to the construction of a user-friendly, engaging alcohol intervention.

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It is generally accepted that both surface chemistry and biochemical cues affect mesenchymal stem cell (MSC) proliferation and differentiation. Several growth factors that have strong influences on MSC behavior bind to glycosaminoglycans in interactions that affect their stability and their biochemical activity. The goal of this work was to develop polysaccharide-based polyelectrolyte multilayers (PEMs) to bind and stabilize growth factors for delivery to MSCs.

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