Unintended Consequences: A Case Study of a Toddler's Accidental Burn Injury Caused by a Hair Crimper.

ABSTRACT: Recognizing when an injury is concerning for abuse is of utmost importance, as failure to do so places the child at a significant risk for further inflicted injury. Misinterpreting accidental injury as abuse can also have dire consequences for a child and their caregivers. The provider must be aware of characteristics of cutaneous injuries, including burns, that are concerning for abuse. Understanding these characteristics and putting them into clinical practice is necessary to protect children from additional abuse and protect families from wrongful accusations. This case report evaluates a 12-month-old boy who presented to a pediatric emergency room with a patterned, full-thickness burn to the leg. After evaluation, we summarized the additional medical evaluation needed, including a focused history and physical examination, and recommended appropriate diagnostic testing needed to evaluate a child of this age for possible child maltreatment.

L-type channel inactivation balances the increased peak calcium current due to absence of Rad in cardiomyocytes.

The L-type Ca2+ channel (LTCC) provides trigger calcium to initiate cardiac contraction in a graded fashion that is regulated by L-type calcium current (ICa,L) amplitude and kinetics. Inactivation of LTCC is controlled to fine-tune calcium flux and is governed by voltage-dependent inactivation (VDI) and calcium-dependent inactivation (CDI). Rad is a monomeric G protein that regulates ICa,L and has recently been shown to be critical to ß-adrenergic receptor (ß-AR) modulation of ICa,L. Our previous work showed that cardiomyocyte-specific Rad knockout (cRadKO) resulted in elevated systolic function, underpinned by an increase in peak ICa,L, but without pathological remodeling. Here, we sought to test whether Rad-depleted LTCC contributes to the fight-or-flight response independently of ß-AR function, resulting in ICa,L kinetic modifications to homeostatically balance cardiomyocyte function. We recorded whole-cell ICa,L from ventricular cardiomyocytes from inducible cRadKO and control (CTRL) mice. The kinetics of ICa,L stimulated with isoproterenol in CTRL cardiomyocytes were indistinguishable from those of unstimulated cRadKO cardiomyocytes. CDI and VDI are both enhanced in cRadKO cardiomyocytes without differences in action potential duration or QT interval. To confirm that Rad loss modulates LTCC independently of ß-AR stimulation, we crossed a ß1,ß2-AR double-knockout mouse with cRadKO, resulting in a Rad-inducible triple-knockout mouse. Deletion of Rad in cardiomyocytes that do not express ß1,ß2-AR still yielded modulated ICa,L and elevated basal heart function. Thus, in the absence of Rad, increased Ca2+ influx is homeostatically balanced by accelerated CDI and VDI. Our results indicate that the absence of Rad can modulate the LTCC without contribution of ß1,ß2-AR signaling and that Rad deletion supersedes ß-AR signaling to the LTCC to enhance in vivo heart function.

Increased Retention of Cardiac Cells to a Glass Substrate through Streptavidin-Biotin Affinity.

In vitro analysis of primary isolated adult cardiomyocyte physiological processes often involves optical imaging of dye-loaded cells on a glass substrate. However, when exposed to rapid solution changes, primary cardiomyocytes often move to compromise quantitative measures. Improved immobilization of cells to glass would permit higher throughput assays. Here, we engineer the peripheral membrane of cardiomyocytes with biotin to anchor cardiomyocytes to borosilicate glass coverslips functionalized with streptavidin. We use a rat cardiac myoblast cell line to determine general relationships between processing conditions, ligand density on the cell and the glass substrate, cellular function, and cell retention under shear flow. Use of the streptavidin-biotin system allows for more than 80% retention of cardiac myoblasts under conventional rinsing procedures, while unmodified cells are largely rinsed away. The adhesion system enables the in-field retention of cardiac cells during rapid fluid changes using traditional pipetting or a modern microfluidic system at a flow rate of 160 mL/min. Under fluid flow, the surface-engineered primary adult cardiomyocytes are retained in the field of view of the microscope, while unmodified cells are rinsed away. Importantly, the engineered cardiomyocytes are functional following adhesion to the glass substrate, where contractions are readily observed. When applying this adhesion system to cardiomyocyte functional analysis, we measure calcium release transients by caffeine induction at an 80% success rate compared to 20% without surface engineering.

Myocardial-restricted ablation of the GTPase RAD results in a pro-adaptive heart response in mice.

Existing therapies to improve heart function target ß-adrenergic receptor (ß-AR) signaling and Ca2+ handling and often lead to adverse outcomes. This underscores an unmet need for positive inotropes that improve heart function without any adverse effects. The GTPase Ras associated with diabetes (RAD) regulates L-type Ca2+ channel (LTCC) current (ICa,L). Global RAD-knockout mice (gRAD-/-) have elevated Ca2+ handling and increased cardiac hypertrophy, but RAD is expressed also in noncardiac tissues, suggesting the possibility that pathological remodeling is due also to noncardiac effects. Here, we engineered a myocardial-restricted inducible RAD-knockout mouse (RADΔ/Δ). Using an array of methods and techniques, including single-cell electrophysiological and calcium transient recordings, echocardiography, and radiotelemetry monitoring, we found that RAD deficiency results in a sustained increase of inotropy without structural or functional remodeling of the heart. ICa,L was significantly increased, with RAD loss conferring a ß-AR-modulated phenotype on basal ICa,L Cardiomyocytes from RADΔ/Δ hearts exhibited enhanced cytosolic Ca2+ handling, increased contractile function, elevated sarcoplasmic/endoplasmic reticulum calcium ATPase 2 (SERCA2a) expression, and faster lusitropy. These results argue that myocardial RAD ablation promotes a beneficial elevation in Ca2+ dynamics, which would obviate a need for increased ß-AR signaling to improve cardiac function.

Neuroproteomic study of nitrated proteins in moderate traumatic brain injured rats treated with gamma glutamyl cysteine ethyl ester administration post injury: Insight into the role of glutathione elevation in nitrosative stress.

PURPOSE: The aims of this study are to establish a time point to determine the most beneficial time to administer GCEE post incident to reduce oxidative damage and second, by using redox proteomics, to determine if GCEE can readily suppress 3-NT modification in TBI animals. EXPERIMENTAL DESIGN: By using a moderate traumatic brain injury model with Wistar rats, it is hypothesized that the role of 3-nitrotyrosine (3-NT) formation as an intermediate will predict the involvement of protein nitration/nitrosation and oxidative damage in the brain. RESULTS: In this experiment, the levels of protein carbonyls, 4-hydroxynonenal, and 3-nitrotyrosine were significantly elevated in TBI injured, saline treated rats compared with those who sustained an injury and were treated with 150 mg/kg of the glutathione mimetic, GCEE. CONCLUSION AND CLINICAL RELEVANCE: Determining the existence of elevated 3-NT levels provides insight into the relationship between the protein nitration/nitrosation and the oxidative damage, which can determine the pathogenesis and progression of specific neurological diseases.

Glycan Biomarkers for Rheumatoid Arthritis and Its Remission Status in Han Chinese Patients.

Rheumatoid arthritis (RA), a systemic, chronic, and progressive inflammatory autoimmune disease, affects up to 1.0% of the world population doubling mortality rate of patients and is a major global health burden. Worrisomely, we lack robust diagnostics of RA and its remission status. Research with the next-generation biomarker technology platforms such as glycomics offers new promises in this context. We report here a clinical case-control study comprising 128 patients suffering from chronic RA (80.22% in remission, 19.78% active clinically) and 195 gender- and age-matched controls, with a view to the putative glycan biomarkers of RA as well as its activity or remission status in Han Chinese RA patients. Hydrophilic interaction liquid chromatography-ultra-performance liquid chromatography (HILIC-UPLC) was used for the analysis of IgG glycans. The regression model identified the glycans that predict RA status, while a receiver operating characteristic (ROC) curve analysis validated the sensitivity and prediction power. Among the total 24 glycan peaks (GP1-GP24), ROC analysis showed only GP1 prediction to be highly sensitive with an area under the curve (AUC) = 0.881. Even though GP21 and GP22 could predict active status among the RA cases (p < 0.05), they had lower sensitivity of prediction with an AUC = 0.658. Taken together, these observations suggest that GP1 might have potential as a putative biomarker for RA in the Han Chinese population, while the change in IgG glycosylation shows association with the RA active and remission states. To the best of our knowledge, this is the first glycomics study with respect to disease activity and remission states in RA.

Therapeutic window analysis of the neuroprotective effects of cyclosporine A after traumatic brain injury.

Mitochondrial dysfunction plays a pivotal role in secondary cell death mechanisms following traumatic brain injury (TBI). Several reports have demonstrated that inhibition of the mitochondrial permeability transition pore with the immunosuppressant drug cyclosporine A (CsA) is efficacious. Accordingly, CsA is being moved forward into late-stage clinical trials for the treatment of moderate and severe TBI. However, several unknowns exist concerning the optimal therapeutic window for administering CsA at the proposed dosages to be used in human studies. The present study utilized a moderate (1.75 mm) unilateral controlled cortical impact model of TBI to determine the most efficacious therapeutic window for initiating CsA therapy. Rats were administered an IP dose of CsA (20 mg/kg) or vehicle at 1, 3, 4, 5, 6, and 8 h post-injury. Immediately following the initial IP dose, osmotic mini-pumps were implanted at these time points to deliver 10 mg/kg/d of CsA or vehicle. Seventy-two hours following the initiation of treatment the pumps were removed to stop CsA administration. Quantitative analysis of cortical tissue sparing 7 days post-injury revealed that CsA treatment initiated at any of the post-injury initiation times out to 8 h resulted in significantly less cortical damage compared to animals receiving vehicle treatment. However, earlier treatment begun in the first 3 h was significantly more protective than that begun at 4 and 8 h. Treatment initiated at 1 h post-injury (∼68% decrease) was not significantly different than that seen at 3 h (∼46% decrease), but resulted in significantly greater cortical tissue sparing compared to CsA treatment initiated at least 4 h post-injury (28% decrease). Together these results illustrate the importance of initiating therapeutic interventions such as CsA as soon as possible following TBI, preferably within 4 h post-injury, to achieve the best possible neuroprotective effect. However, the drug appears to retain some protective efficacy even when initiated as late as 8 h post-injury.

Proteomic identification of nitrated brain proteins in traumatic brain-injured rats treated postinjury with gamma-glutamylcysteine ethyl ester: insights into the role of elevation of glutathione as a potential therapeutic strategy for traumatic brain injury.

Traumatic brain injury (TBI) occurs suddenly and has damaging effects to the brain that are dependent on the severity of insult. Symptoms can be mild, moderate, or severe. Oxidative damage is associated with traumatic brain injury through reactive oxygen/nitrogen species production. One such species, peroxynitrite, is elevated in TBI brain tissue (Orihara et al. [2001] Forensic Sci. Int. 123:142-149; Deng et al. [2007] Exp. Neurol. 205:154-165). Peroxynitrite can react with carbon dioxide and decompose to produce NO(2) and carbonate radicals, which in turn can lead to 3-nitrotyrosine, an index of protein nitration. Gamma-glutamylcysteine ethyl ester (GCEE) is an ethyl ester moiety of gamma-glutamylcysteine, an agent that up-regulates glutathione (GSH) production in brain (Drake et al. [2002] J. Neurosci. Res. 68:776-784). Many preclinical studies of TBI have employed pretreatment of animals with proposed beneficial agents prior to the injury itself. However, in the real world of TBI, treatment begins postinjury. Hence, insights into agents that improve outcome following injury are desperately needed. This study is one of the first to investigate a potential GSH-based therapy for TBI postinjury. Protein carbonyls, an index of protein oxidation, were significantly elevated in brain of animals subjected to TBI. However, if, after TBI, GCEE was administered i.p., protein carbonyl levels were significantly reduced. Similarly, 3-nitrotyrosine levels were elevated in brain following TBI but significantly decreased following TBI if GCEE was administered i.p. Redox proteomics analysis showed that several brain proteins were nitrated after TBI. However, if GCEE was given i.p. following TBI, many of these proteins were protected from nitration. The results are encouraging and are discussed with reference to potential therapeutic strategies for TBI involving elevated GSH.

Post-Injury Administration of Mitochondrial Uncouplers Increases Tissue Sparing and Improves Behavioral Outcome following Traumatic Brain Injury in Rodents.

Following experimental traumatic brain injury (TBI), a rapid and significant necrosis occurs at the site of injury which coincides with significant mitochondrial dysfunction. The present study is driven by the hypothesis that TBI-induced glutamate release increases mitochondrial Ca(2+)cycling/overload, ultimately leading to mitochondrial dysfunction. Based on this premise, mitochondrial uncoupling during the acute phases of TBI-induced excitotoxicity should reduce mitochondrial Ca(2+) uptake (cycling) and reactive oxygen species (ROS) production since both are mitochondrial membrane potential dependent. In the present study, we utilized a cortical impact model of TBI to assess the potential use of mitochondrial uncouplers (2,4-DNP, FCCP) as a neuroprotective therapy. Young adult male rats were intraperitoneally administered vehicle (DMSO), 2,4-DNP (5 mg/kg), or FCCP (2.5 mg/kg) at 5 min post-injury. All animals treated with the uncouplers demonstrated a significant reduction in the amount of cortical damage and behavioral improvement following TBI. In addition, mitochondria isolated from the injured cortex at 3 or 6 h post-injury demonstrated that treatment with the uncouplers significantly improved several parameters of mitochondrial bioenergetics. These results demonstrate that post-injury treatment with mitochondrial uncouplers significantly (p < 0.01) increases cortical tissue sparing ( approximately 12%) and significantly (p< 0.01) improves behavioral outcome following TBI. The mechanism of neuroprotection most likely involves the maintenance of mitochondrial homeostasis by reducing mitochondrial Ca(2+) loading and subsequent mitochondrial dysfunction. These results further implicate mitochondrial dysfunction as an early event in the pathophysiology of TBI and that targeting acute mitochondrial events can result in long-term neuroprotection and improve behavioral outcome following brain injury.