Are asymptomatic carriers of OTC deficiency always asymptomatic? A multicentric retrospective study of risk using the UCDC longitudinal study database.

BACKGROUND: Ornithine transcarbamylase deficiency (OTCD) due to an X-linked OTC mutation, is responsible for moderate to severe hyperammonemia (HA) with substantial morbidity and mortality. About 80% of females with OTCD remain apparently "asymptomatic" with limited studies of their clinical characteristics and long-term health vulnerabilities. Multimodal neuroimaging studies and executive function testing have shown that asymptomatic females exhibit limitations when stressed to perform at higher cognitive load and had reduced activation of the prefrontal cortex. This retrospective study aims to improve understanding of factors that might predict development of defined complications and serious illness in apparent asymptomatic females. A proband and her daughter are presented to highlight the utility of multimodal neuroimaging studies and to underscore that asymptomatic females with OTCD are not always asymptomatic. METHODS: We review data from 302 heterozygote females with OTCD enrolled in the Urea Cycle Disorders Consortium (UCDC) longitudinal natural history database. We apply multiple neuroimaging modalities in the workup of a proband and her daughter. RESULTS: Among the females in the database, 143 were noted as symptomatic at baseline (Sym). We focused on females who were asymptomatic (Asx, n = 111) and those who were asymptomatic initially upon enrollment in study but who later became symptomatic sometime during follow-up (Asx/Sym, n = 22). The majority of Asx (86%) and Asx/Sym (75%) subjects did not restrict protein at baseline, and ~38% of Asx and 33% of Asx/Sym subjects suffered from mild to severe neuropsychiatric conditions such as mood disorder and sleep problems. The risk of mild to severe HA sometime later in life for the Asx and Asx/Sym subjects as a combined group was ~4% (5/133), with ammonia ranging from 77 to 470 µM and at least half (2/4) of subjects requiring hospital admission and nitrogen scavenger therapy. For this combined group, the median age of first HA crisis was 50 years, whereas the median age of first symptom which included neuropsychiatric and/or behavioral symptoms was 17 years. The multimodal neuroimaging studies in female heterozygotes with OTCD also underscore that asymptomatic female heterozygotes with OTCD (e.g., proband) are not always asymptomatic. CONCLUSIONS: Analysis of Asx and Asx/Sym females with OTCD in this study suggests that future evidence-based management guidelines and/or a clinical risk score calculator for this cohort could be useful management tools to reduce morbidity and improve long-term quality of life.

Native T1 values identify myocardial changes and stratify disease severity in patients with Duchenne muscular dystrophy.

BACKGROUND: Duchenne muscular dystrophy (DMD) is an X-linked, inherited disorder causing dilated cardiomyopathy with variable onset and progression. Currently we lack objective markers of the effect of therapies targeted towards preventing progression of subclinical cardiac disease. Thus, our aim was to compare the ability of native T1 and extracellular volume (ECV) measurements to differentiate risk of myocardial disease in DMD and controls. METHODS: Twenty boys with DMD and 16 age/gender-matched controls without history predisposing to cardiac fibrosis, but with a clinical indication for cardiovascular magnetic resonance (CMR) evaluation, underwent CMR with contrast. Data points collected include left ventricular ejection fraction (LVEF), left ventricular mass, and presence of late gadolinium enhancement (LGE). Native T1, and ECV regional mapping were obtained using both a modified Look-Locker (MOLLI) and saturation recovery single shot sequence (SASHA) on a 1.5T scanner. Using ordinal logistic regression models, controlling for age and LVEF, LGE-free septal we evaluated the ability native T1 and ECV assessments to differentiate levels of cardiomyopathy. RESULTS: Twenty DMD subjects aged 14.4 ± 4 years had an LVEF of 56.3 ± 7.4 %; 12/20 had LGE, all confined to the lateral wall. Sixteen controls aged 16.1 ± 2.2 years had an LVEF 60.4 ± 5.1 % and no LGE. Native T1 and ECV values were significantly higher in the DMD group (p < 0.05) with both MOLLI and SASHA imaging techniques. Native T1 demonstrated a 50 % increase in the ability to predict disease state (control, DMD without fibrosis, DMD with fibrosis). ECV demonstrated only the ability to predict presence of LGE, but could not distinguish between controls and DMD without fibrosis. CONCLUSIONS: LGE-spared regions of boys with DMD have significantly different native T1 and ECV values compared to controls. Native T1 measurements can identify early changes in DMD patients without the presence of LGE and help predict disease severity more effectively than ECV. Native T1 may be a novel outcome measure for early cardiac therapies in DMD and other cardiomyopathies.

Initial report of the osteogenesis imperfecta adult natural history initiative.

BACKGROUND: A better understanding of the natural history of osteogenesis imperfecta (OI) in adulthood should improve health care for patients with this rare condition. METHODS: The Osteogenesis Imperfecta Foundation established the Adult Natural History Initiative (ANHI) in 2010 to give voice to the health concerns of the adult OI community and to begin to address existing knowledge gaps for this condition. Using a web-based platform, 959 adults with self-reported OI, representing a wide range of self-reported disease severity, reported symptoms and health conditions, estimated the impact of these concerns on present and future health-related quality of life (QoL) and completed a Patient-Reported Outcomes Measurement Information System (PROMIS®) survey of health issues. RESULTS: Adults with OI report lower general physical health status (p < .0001), exhibit a higher prevalence of auditory (58% of sample versus 2-16% of normalized population) and musculoskeletal (64% of sample versus 1-3% of normalized population) concerns than the general population, but report generally similar mental health status. Musculoskeletal, auditory, pulmonary, endocrine, and gastrointestinal issues are particular future health-related QoL concerns for these adults. Numerous other statistically significant differences exist among adults with OI as well as between adults with OI and the referent PROMIS® population, but the clinical significance of these differences is uncertain. CONCLUSIONS: Adults with OI report lower general health status but are otherwise more similar to the general population than might have been expected. While reassuring, further analysis of the extensive OI-ANHI databank should help identify areas of unique clinical concern and for future research. The OI-ANHI survey experience supports an internet-based strategy for successful patient-centered outcomes research in rare disease populations.

The hemoglobin glycation index identifies subpopulations with harms or benefits from intensive treatment in the ACCORD trial.

OBJECTIVE: This study tested the hypothesis that intensive treatment in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial disproportionately produced adverse outcomes in patients with diabetes with a high hemoglobin glycation index (HGI = observed HbA1c - predicted HbA1c). RESEARCH DESIGN AND METHODS: ACCORD was a randomized controlled trial of 10,251 patients with type 2 diabetes assigned to standard or intensive treatment with HbA1c goals of 7.0% to 7.9% (53 to 63 mmol/mol) and less than 6% (42 mmol/mol), respectively. In this ancillary study, a linear regression equation (HbA1c = 0.009 × fasting plasma glucose [FPG] [mg/dL] + 6.8) was derived from 1,000 randomly extracted participants at baseline. Baseline FPG values were used to calculate predicted HbA1c and HGI for the remaining 9,125 participants. Kaplan-Meier and Cox regression were used to assess the effects of intensive treatment on outcomes in patients with a low, moderate, or high HGI. RESULTS: Intensive treatment was associated with improved primary outcomes (composite of cardiovascular events) in the low (hazard ratio [HR] 0.75 [95% CI 0.59-0.95]) and moderate (HR 0.77 [95% CI 0.61-0.97]) HGI subgroups but not in the high HGI subgroup (HR 1.14 [95% CI 0.93-1.40]). Higher total mortality in intensively treated patients was confined to the high HGI subgroup (HR 1.41 [95% CI 1.10-1.80]). A high HGI was associated with a greater risk for hypoglycemia in the standard and intensive treatment groups. CONCLUSIONS: HGI calculated at baseline identified subpopulations in ACCORD with harms or benefits from intensive glycemic control. HbA1c is not a one-size-fits-all indicator of blood glucose control, and taking this into account when making management decisions could improve diabetes care.

Association between Inflammation and Biological Variation in Hemoglobin A1c in U.S. Nondiabetic Adults.

CONTEXT: Inflammation is associated with higher glycated hemoglobin (HbA1c) levels. Whether the relationship is independent of blood glucose concentration remains unclear. OBJECTIVE: The hemoglobin glycation index (HGI) was used to test the hypothesis that interindividual variation in HbA1c is associated with inflammation. PARTICIPANTS: This study used nondiabetic adults from the National Health and Nutrition Examination Survey (1999-2008). MAIN OUTCOME MEASURES: A subsample of participants was used to estimate the linear regression relationship between HbA1c and fasting plasma glucose (FPG). Predicted HbA1c were calculated for 7323 nondiabetic participants by inserting FPG into the equation, HbA1c = 0.017 × FPG (mg/dL) + 3.7. HGI was calculated as the difference between the observed and predicted HbA1c and the population was divided into low, moderate, and high HGI subgroups. Polymorphonuclear leukocytes (PMNL), monocytes, and C-reactive protein (CRP) were used as biomarkers of inflammation. RESULTS: Mean HbA1c, CRP, monocyte, and PMNL levels, but not FPG, progressively increased in the low, moderate, and high HGI subgroups. There were disproportionately more Blacks than whites in the high HGI subgroup. CRP (ß, 0.009; 95% confidence interval [CI], 0.0001-0.017), PMNL (ß, 0.036; 95% CI, 0.010-0.062), and monocyte count (ß, 0.072; 95% CI, 0.041-0.104) were each independent predictors of HGI after adjustment for age, sex, race, triglycerides, hemoglobin level, mean corpuscular volume, red cell distribution width, and obesity status. CONCLUSIONS: HGI reflects the effects of inflammation on HbA1c in a nondiabetic population of U.S. adults and may be a marker of risk associated with inflammation independent of FPG, race, and obesity.

Propranolol vs prednisolone for symptomatic proliferating infantile hemangiomas: a randomized clinical trial.

IMPORTANCE: While propranolol is touted as superior to prednisolone for treating infantile hemangiomas (IH), a randomized clinical trial (RCT) comparing the outcome and tolerability of these medications for symptomatic, proliferating IH has not been reported. OBJECTIVES: To determine if oral propranolol is more efficacious and better tolerated than prednisolone in treating symptomatic, proliferating IH and to determine the feasibility of conducting a multi-institutional, RCT comparing efficacy and tolerability of both medications. DESIGN, SETTING, AND PARTICIPANTS: Phase 2, investigator-blinded, multi-institutional RCT conducted in 3 academic vascular anomalies clinics on 19 of 44 eligible infants aged between 2 weeks and 6 months. All participating patients had symptomatic proliferating IH treated between September 1, 2010, and August 1, 2012. INTERVENTIONS: Treatment with oral propranolol vs prednisolone (2.0 mg/kg/d) until halted owing to toxic effects or clinical response. MAIN OUTCOMES AND MEASURES: Primary outcome was change in IH size after 4 months of therapy. Secondary outcomes were response rate and frequency and severity of adverse events (AEs). RESULTS: The primary outcome showed no difference in lesion size or affected skin area after 4 months of therapy: 41% and 1.32 mm2 for prednisolone vs 64% and 0.55 mm2 for propranolol (P = .12 for lesion size, and P = .56 for affected skin area). Longitudinal analyses showed a faster response in total lesion outer dimension with prednisolone (P = .03), but this advantage over time was not noted when central clearing and outer dimension were included in the analysis (P = .91). The overall frequency of AEs was similar (44 for prednisolone vs 32 for propranolol) (P = .84), but prednisolone-treated participants had more grade 3 severe AEs (11 vs 1) (P = .01), particularly growth retardation resulting in size and weight below the fifth percentile. Early study withdrawal owing to AEs occurred in 6 (75%) of 8 patients in the prednisolone group but 0 of 11 propranolol-treated participants. The mean duration of therapy was shorter for prednisolone (141 vs 265 days), reflecting the higher rate of early withdrawals. CONCLUSIONS AND RELEVANCE: Both medications show similar efficacy for reducing the area of symptomatic, proliferating IH. Although prednisolone showed a faster response rate, propranolol was better tolerated with significantly fewer severe AEs. Propranolol should be the first line of therapy for symptomatic IH unless contraindicated or unless future studies demonstrate severe AEs from propranolol. Recruiting participants for a phase 3 RCT would be difficult owing to safety profiles measured here and emerging trends favoring propranolol. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00967226.

Intranasal epidermal growth factor treatment rescues neonatal brain injury.

There are no clinically relevant treatments available that improve function in the growing population of very preterm infants (less than 32 weeks' gestation) with neonatal brain injury. Diffuse white matter injury (DWMI) is a common finding in these children and results in chronic neurodevelopmental impairments. As shown recently, failure in oligodendrocyte progenitor cell maturation contributes to DWMI. We demonstrated previously that the epidermal growth factor receptor (EGFR) has an important role in oligodendrocyte development. Here we examine whether enhanced EGFR signalling stimulates the endogenous response of EGFR-expressing progenitor cells during a critical period after brain injury, and promotes cellular and behavioural recovery in the developing brain. Using an established mouse model of very preterm brain injury, we demonstrate that selective overexpression of human EGFR in oligodendrocyte lineage cells or the administration of intranasal heparin-binding EGF immediately after injury decreases oligodendroglia death, enhances generation of new oligodendrocytes from progenitor cells and promotes functional recovery. Furthermore, these interventions diminish ultrastructural abnormalities and alleviate behavioural deficits on white-matter-specific paradigms. Inhibition of EGFR signalling with a molecularly targeted agent used for cancer therapy demonstrates that EGFR activation is an important contributor to oligodendrocyte regeneration and functional recovery after DWMI. Thus, our study provides direct evidence that targeting EGFR in oligodendrocyte progenitor cells at a specific time after injury is clinically feasible and potentially applicable to the treatment of premature children with white matter injury.

The use of near-infrared spectroscopy during an extubation readiness trial as a predictor of extubation outcome.

OBJECTIVES: To determine whether the measurement of cerebral and somatic regional oxygen saturation during an extubation readiness trial predicts extubation failure in postoperative cardiac patients. DESIGN: Prospective observational study. SETTING: Tertiary care center cardiac ICU. PATIENTS: Pediatric patients 1 day to 21 years old following cardiac surgery for congenital heart disease. Patients were included if they were intubated for greater than 12 hours and were undergoing an extubation readiness trial. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Data collection included patient demographic, procedural, laboratory, and physiologic variables. Regional oxygen saturation values were recorded using near-infrared spectroscopy at baseline, during a 2-hour extubation readiness trial, and in the first 2 hours postextubation. Ninety-nine extubation readiness trials were conducted in 79 patients. Adjusting for baseline somatic regional oxygen saturation, logistic regression analysis demonstrated that patients with a decline in their minimum somatic regional oxygen saturation of at least 10% during an extubation readiness trial had a 6-time increased odds of extubation failure (p = 0.02; 95% CI, 1.26-29.8). Receiver-operating characteristic curve analysis demonstrated that a 12% decline in the minimum regional oxygen saturation best predicted extubation failure with 54% sensitivity and 82% specificity. CONCLUSIONS: A 12% decline in somatic regional oxygen saturation during an extubation readiness trial is associated with an increased risk of extubation failure following a successful extubation readiness trial. The addition of somatic regional oxygen saturation measurements to an extubation readiness trial may improve our ability to predict extubation outcome.

Analysis of pediatric autologous PBSC apheresis and transplant: age is a major factor affecting post-transplant toxicity.

BACKGROUND: High-dose chemotherapy followed by autologous hematopoietic cell transplantation (HCT) is used in many therapeutic protocols for pediatric intra- and extra-cranial solid tumors. HCT can be curative, but is associated with significant toxicity. PROCEDURE: Between January 2001 and June 2009, 92 solid tumor patients (age 6 months to 27 years) underwent 94 autologous apheresis procedures at Children's National Medical Center. Out of that group, 71 patients, who underwent 162 autologous HCT, were analyzed for transplant outcomes. Multiple variable modeling was used to identify independent variables related to transplant toxicity outcome measures, such as bacteremia, intensive care admission, and death. Other outcome measures (time to pre-apheresis peripheral blood CD34+ count, product yield, and time to engraftment) were also analyzed. Independent variables included patient-specific variables (age, weight, tumor type, chemotherapy administered, and primary vs. relapsed disease) and harvest or transplant-related variables (total white blood cell and CD34+ cell counts prior to transplant, and quantity of total nucleated cells and CD34+ cells infused during transplant). RESULTS: Transplant toxicity was significantly greater in younger patients (P = 0.001) and in neuroblastoma patients (P = 0.003). The time to neutrophil engraftment, controlling for weight, age, and chemotherapy, was positively related to absolute CD34+ cells/kg infused (P = 0.01). The time to CD34+ recovery pre-apheresis was affected by patient diagnosis (P = 0.05). CONCLUSIONS: Younger patients had increased transplant toxicity, with infants <1 year of age at highest risk for fever, bacteremia, admission to intensive care, and death. Infants would likely benefit from hospitalization after autologous HCT until neutrophil recovery.

Does prearrival communication from a poison center to an emergency department decrease time to activated charcoal for pediatric poisoning?

OBJECTIVE: A poison center plays an important role in directing appropriate care, which is critical in reducing morbidity due to poisoning. Activated charcoal (AC) is one intervention for some poisonings. This study examined whether children with a poisoning who were preannounced by a poison center received AC earlier than patients without a referral. METHODS: A retrospective review of AC administration in children aged 0 to 18 years in a pediatric emergency department (ED) from 2000 to 2006 was performed. Abstracted covariates were poison center referral status, age, sex, acuity, disposition, transportation mode, triage time, and time of AC administration. Analysis of variance controlling for covariates tested the equality of mean time intervals between the groups with and without a poison center referral. RESULTS: Three hundred fifty-one cases met the inclusion criteria. One hundred thirty-five (39%) were male. Eighty cases (23%) had a poison center referral. Time from triage to charcoal administration for patients with a poison center referral was a mean of 59 (SD, 34) minutes. Time for the group without a referral was a mean of 71 (SD, 43) minutes (P = 0.0036). CONCLUSIONS: Advanced communication from a poison center was associated with earlier administration of AC in the ED for this population. Nevertheless, the duration to charcoal administration was frequently suboptimal. Triage and prehospital practices should be reexamined to improve timeliness of AC when indicated and consider exclusion of administration if beyond an appropriate time frame. Advanced notification should be the paradigm for all poison centers, and early response protocols for poison center referrals should be used by EDs.

Inverse zonation of hepatocyte transduction with AAV vectors between mice and non-human primates.

Gene transfer vectors based on adeno-associated virus 8 (AAV8) are highly efficient in liver transduction and can be easily administered by intravenous injection. In mice, AAV8 transduces predominantly hepatocytes near central veins and yields lower transduction levels in hepatocytes in periportal regions. This transduction bias has important implications for gene therapy that aims to correct metabolic liver enzymes because metabolic zonation along the porto-central axis requires the expression of therapeutic proteins within the zone where they are normally localized. In the present study we compared the expression pattern of AAV8 expressing green fluorescent protein (GFP) in liver between mice, dogs, and non-human primates. We confirmed the pericentral dominance in transgene expression in mice with AAV8 when the liver-specific thyroid hormone-binding globulin (TBG) promoter was used but also observed the same expression pattern with the ubiquitous chicken ß-actin (CB) and cytomegalovirus (CMV) promoters, suggesting that transduction zonation is not caused by promoter specificity. Predominantly pericentral expression was also found in dogs injected with AAV8. In contrast, in cynomolgus and rhesus macaques the expression pattern from AAV vectors was reversed, i.e. transgene expression was most intense around portal areas and less intense or absent around central veins. Infant rhesus macaques as well as newborn mice injected with AAV8 however showed a random distribution of transgene expression with neither portal nor central transduction bias. Based on the data in monkeys, adult humans treated with AAV vectors are predicted to also express transgenes predominantly in periportal regions whereas infants are likely to show a uniform transduction pattern in liver.

The effect of dexmedetomidine during myringotomy and pressure-equalizing tube placement in children.

BACKGROUND: Bilateral myringotomy (BMT) is a commonly performed otolaryngologic procedure in children. OBJECTIVES: To examine the effects of intranasal dexmedetomidine, an α(2)-adrenoceptor agonist, on time-averaged pain scores, pain control, need for rescue analgesia, and agitation scores in children undergoing BMT. METHODS: We designed a trial to enroll 160 children randomized to one of four groups: two study groups, dexmedetomidine (1 or 2 µg·kg(-1)), or two control groups representing our institutional standards of practice (intranasal fentanyl-2 µg·kg(-1) or acetaminophen as needed postoperatively). RESULTS: After 101 children were enrolled, patient caregivers observed that some enrollees were excessively sedated and required prolonged postanesthesia care unit (PACU) stay. This observation led to an unplanned interim analysis and early trial termination. After data were collected, severe nonnormality of pain and agitation scores necessitated a switch of the outcome to assess repeated measurements of the proportion of patients with pain, severe pain, and agitation. Demographics, time to emergence, and agitation were similar among all groups. The risk of requiring acetaminophen rescue (P < 0.0001) and proportion of patients having pain (P = 0.016) was significantly higher in one control group (rescue analgesia only) compared with fentanyl or dexmedetomidine groups. Importantly, length of stay in the PACU was significantly longer in dexmedetomidine-2 µg·kg(-1)-treated compared with dexmedetomidine-1 µg·kg(-1)-treated, fentanyl-treated, or the control group, P = 0.0037. CONCLUSIONS: In this trial, we were unable to answer the original question as to the role of dexmedetomidine on time-averaged pain and agitation scores after BMT. However, our findings clearly demonstrate that in children undergoing BMT, at higher doses, dexmedetomidine significantly prolongs length of stay in the PACU.

High-dose dexmedetomidine increases the opioid-free interval and decreases opioid requirement after tonsillectomy in children.

PURPOSE: Dexmedetomidine, a selective α(2) adrenoreceptor agonist, has analgesic and sedative properties, minimal impact on respiratory parameters, and reportedly decreases analgesic requirements after surgery. Given its pharmacodynamic profile, dexmedetomidine might have a role for postoperative pain control in children undergoing tonsillectomy. In this study, we hypothesized that dexmedetomidine would delay and decrease opioid requirements after tonsillectomy. METHODS: In a double-blind controlled trial, participants undergoing tonsillectomy were randomized to receive one intravenous dose of fentanyl (1 µg·kg(-1) or 2 µg·kg(-1)) or dexmedetomidine (2 µg·kg(-1) or 4 µg·kg(-1)) immediately after endotracheal intubation. Primary outcomes included requirement for rescue morphine in the initial postoperative period. RESULTS: One hundred and one children were enrolled. During the postoperative period, dexmedetomidine (2 and 4 µg·kg(-1) groups combined) significantly prolonged the opioid-free interval of children who underwent tonsillectomy compared with fentanyl (1 and 2 µg·kg(-1) groups combined) (P < 0.001). Children treated with dexmedetomidine 2 µg·kg(-1) vs dexmedetomidine 4 µg·kg(-1) had similar cumulative incidence curves for time to morphine rescue, whereas there was a small difference in time to first morphine rescue administration when comparing fentanyl 1 µg·kg(-1) vs fentanyl 2 µg·kg(-1). Furthermore, length of stay in the postanesthesia care unit was significantly longer for children treated with dexmedetomidine vs children treated with fentanyl (P = 0.0016). CONCLUSIONS: High-dose dexmedetomidine decreases opioid requirements, prolongs the opioid-free interval after tonsillectomy, and prolongs length of stay in the postanesthesia care unit. It is conceivable that these early opioid-sparing effects could benefit patients at risk for respiratory complications early in the postoperative course after tonsillectomy (e.g., patients with obstructive sleep apnea). (ClinicalTrials.gov number, NCT00654511).

Hemoglobin glycation index: a robust measure of hemoglobin A1c bias in pediatric type 1 diabetes patients.

BACKGROUND: The hemoglobin glycation index (HGI) assesses biological variation in A1c after accounting for the effect of mean blood glucose (MBG). Previous studies minimized analytical variation that could mask biological variation and showed that HGI was consistent within individuals over time and positively associated with risk for microvascular complications. We tested the hypothesis that biological variation in A1c can be assessed by HGI calculated using routine MBG and A1c data obtained from a typical diabetes clinic. METHODS: Self-monitored MBG and A1c were collected from charts of 202 pediatric type 1 diabetes patients attending 1612 clinic visits over 6 yr. Predicted A1c was calculated from the linear regression equation of A1c on MBG in the study population. HGI was calculated by subtracting predicted A1c from observed A1c. Patients were divided into low, moderate, and high HGI tertile groups. RESULTS: Patients used 12 models of glucose meters. Download protocols varied with clinical practice over time. A1c was measured by multiple assays and laboratories. Despite this analytical heterogeneity, HGI was significantly different between individuals and correlated within individuals. MBG (mean ± SD, mg/dL) was similar in the low (186 ± 31), moderate (195 ± 28), and high (199 ± 42) HGI groups. A1c (%) was significantly different (p < 0.0001) in the low (7.6 ± 0.7), moderate (8.4 ± 0.7), and high (9.6 ± 1.1) HGI groups. CONCLUSION: Biological variation in A1c is a robust quantitative trait that can be assessed using HGI calculated from routine clinic data. This suggests that HGI could be used clinically for more personalized assessment of complications risk.

Labile A1C is inversely correlated with the hemoglobin glycation index in children with type 1 diabetes.

OBJECTIVE: We hypothesized that labile A1C (LA1C) is directly correlated with stable A1C (SA1C) and between-patient differences in SA1C, which are independent of mean blood glucose (MBG). RESEARCH DESIGN AND METHODS: We measured SA1C, LA1C, MBG, and a single clinic capillary glucose (CCG) from 152 pediatric patients with type 1 diabetes. Patients were grouped as high, moderate, or low glycators by hemoglobin glycation index (HGI). RESULTS: LA1C and SA1C were correlated with CCG and MBG. LA1C was not correlated with SA1C (r = 0.06, P = 0.453). LA1C level was significantly associated with glycator group status (P < 0.0019) and CCG (P < 0.0001). Adjusted LA1C levels were highest in the low-HGI patients and lowest in the high-HGI group. CONCLUSIONS: A conventional model of SA1C being directly correlated with LA1C concentration was not confirmed. Between-patient differences in SA1C at the same MBG may be due to complex intracellular factors influencing formation of SA1C from LA1C.

Systematic evaluation of AAV vectors for liver directed gene transfer in murine models.

Vectors based on adeno-associated viruses (AAVs) are being evaluated for use in liver-directed gene therapy. Candidates have been preselected on the basis of capsid structure that plays an important role in determining performance profiles. We describe a comprehensive and statistically powered set of mouse studies designed to compare the performance of vectors based on seven novel AAV capsids. The key criteria used to select candidates for successful gene therapy are high level and stable transgene expression in the absence of toxicity. Based on these criteria, the best performing vectors, AAV8, AAVhu.37, and AAVrh.8, will be further evaluated in nonhuman primates (NHPs).

A Mastery Rubric: guiding curriculum design, admissions and development of course objectives.

This article describes a 'Mastery Rubric' (MR) used to design both the curriculum and the assessments in a new two-year certificate programme intended to train physicians in clinical research skills. The MR for clinical research skills is built around a set of core research skills: critical review of literature; articulation of research objective; development of research design; development of analysis plan; implementation of the study; implementation of the analysis plan and presentation of results. Four distinct levels of performance are described for each skill: beginning, novice, competent and proficient. This rubric outlines and provides a path to mastery of the clinical research skills the certificate programme was designed and funded to target. Using the rubric to design the curriculum ensures that courses will provide instruction in key domains, promotes assessment that demonstrates development in the target skills and knowledge, and encourages reflection and cognitive self-monitoring in the students. It is a flexible, criterion-referenced definition of 'success' for students as well as the programme itself. The criteria are characterised in terms of the skills, habits of mind and organisational principles that can foster excellence in clinical research, but the approach can be generalised.