Pediatric Bilateral Lumbosacral Dislocation Without Fracture: An Exemplary Case and Literature Review.

Lumbosacral facet dislocations are rare lesions typically seen in high-energy trauma. This type of injury is a severe flexion-distraction injury and is extremely rare, with only six other documented reports. A recent case series proposed a classification for lumbosacral injuries which would classify the present case as a 1C, meaning a bilateral dislocation with anterior slippage of the L5 vertebra without fractures of the articulating processes (AP), pars interarticularis (PI), or vertebral bodies (VB). In this case report, we discuss the third case of a class 1C injury in a pediatric patient, review the associated literature and discuss the presentation, diagnosis, management, and prognosis of these rare dislocations.

Prolactin at moderately increased levels confers a neuroprotective effect in non-secreting pituitary macroadenomas.

CONTEXT: Prolactin, a hormone synthesized by the anterior pituitary gland demonstrates promise as a neuroprotective agent, however, its role in humans and in vivo during injury is not fully understood. OBJECTIVE: To investigate whether elevated levels of prolactin attenuate injury to the retinal nerve fiber layer (RNFL) following compression of the optic chiasm in patients with a prolactin secreting pituitary macroadenoma (i.e., prolactinoma). DESIGN SETTING AND PARTICIPANTS: A retrospective cross-sectional study of all pituitary macroadenoma patients treated at a single institution between 2009 and 2019. MAIN OUTCOME MEASURE(S): Primary outcome measures included RNFL thickness, mean deviation, and prolactin levels for both prolactin-secreting and non-secreting pituitary macroadenoma patients. RESULTS: Sixty-six patients met inclusion criteria for this study (14 prolactin-secreting and 52 non-secreting macroadenoma patients). Of 52 non-secreting macroadenoma patients, 12 had moderate elevation of prolactin secondary to stalk effect. Patients with moderate elevation in prolactin demonstrated increased RNFL thickness compared to patients with normal prolactin levels (p < 0.01). Additionally, a significant positive relation between increasing levels of prolactin and RNFL thickness was identified in patients with moderate prolactin elevation (R = 0.51, p-value = 0.035). No significant difference was identified between prolactinoma patients and those with normal prolactin levels. CONCLUSIONS: Moderately increased serum prolactin is associated with increased RNFL thickness when compared to controls. These associations are lost when serum prolactin is < 30 ng/ml or elevated in prolactinomas. This suggests a neuroprotective effect of prolactin at moderately increased levels in preserving retinal function during optic chiasm compression.

A Quality Improvement Initiative to Improve Attention-Deficit/Hyperactivity Disorder Follow-Up Rates Using School-Based Telemedicine.

OBJECTIVE: Patients with a new diagnosis of attention-deficit/hyperactivity disorder (ADHD) who are prescribed stimulant medication need regular follow-up. Guidelines recommend follow-up within 30 days of stimulant initiation or change but this goal is seldom achieved. This quality improvement (QI) study in an urban academic outpatient practice aimed to: 1) assess whether use of school-based telemedicine increases rates of follow-up within 30 days and decreases the number of days to follow-up for ADHD, and 2) compare rates of 30-day follow-up via in-person vs telemedicine visits. METHODS: We performed three Plan-Do-Study-Act cycles over a 12-month period: QI interventions included clinic wide education, paper prompts for clinicians, and creation of a database to track ADHD patients. We measured days from the index visit to the follow-up visit, and the mode of both visits (in-person or telemedicine). Data were collected for 6 months pre-intervention and 12 months post-intervention. RESULTS: Follow-up within 30 days increased from 19% (of 191 visits) to 33% (of 661 visits) (P < .001). The time to follow-up decreased from 67 to 34 days (P < .001). Follow up visits by telemedicine were more also more likely to be within 30 days (62% vs. 32%, P < .001). DISCUSSION: A QI intervention for ADHD care increased rates of follow-up within 30 days, particularly when telemedicine was used, and decreased the number of days to follow-up. This intervention could serve as a model to improve follow-up for ADHD in other settings.

Nurse-delivered outpatient asthma education for children and caregivers: a pilot study to promote shared asthma management.

OBJECTIVES: To assess the feasibility of nurse-delivered asthma education for caregiver/child dyads in a busy clinic setting, and measure the preliminary effectiveness of the intervention. METHODS: We conducted a pilot study of nurse-delivered asthma education in a busy outpatient clinic. We enrolled a convenience sample of children (7-16 years) with uncontrolled persistent asthma who had a prescription for an inhaled controller medication and public health insurance. After provider visits, nurses taught dyads using picture-based materials, teach-back methods, and colored labels applied to asthma medications. The intervention was repeated at 1-month follow-up. We assessed feasibility by reviewing nurse documentation in the electronic medical record, detailing whether each component was implemented and the time required for education at each visit. We measured preliminary effectiveness by surveying children and caregivers separately before each clinic visit about asthma management responsibility, self-efficacy, caregiver quality of life, and symptoms; caregivers also completed a final telephone survey 2 months after the follow-up visit. We examined pre-post differences in continuous outcomes within-subjects using Wilcoxon signed rank tests. RESULTS: We enrolled 22 child/caregiver dyads. Nursing documentation indicated a high rate of component delivery at each visit; the initial and 1-month visits required 25 and 15 min, respectively. We observed significant increases in child responsibility, child/caregiver self-efficacy, caregiver quality of life, and child symptoms at each follow-up. CONCLUSION: This intervention of patient-centered asthma education can be delivered by nurses to caregiver/child dyads with high fidelity in a busy pediatric practice. Preliminary data indicate potential benefit for both children and caregivers.

Release of Applied Mechanical Loading Stimulates Intercellular Calcium Waves in Drosophila Wing Discs.

Mechanical forces are critical but poorly understood inputs for organogenesis and wound healing. Calcium ions (Ca2+) are critical second messengers in cells for integrating environmental and mechanical cues, but the regulation of Ca2+ signaling is poorly understood in developing epithelial tissues. Here we report a chip-based regulated environment for microorgans that enables systematic investigations of the crosstalk between an organ's mechanical stress environment and biochemical signaling under genetic and chemical perturbations. This method enabled us to define the essential conditions for generating organ-scale intercellular Ca2+ waves in Drosophila wing discs that are also observed in vivo during organ development. We discovered that mechanically induced intercellular Ca2+ waves require fly extract growth serum as a chemical stimulus. Using the chip-based regulated environment for microorgans, we demonstrate that not the initial application but instead the release of mechanical loading is sufficient, but not necessary, to initiate intercellular Ca2+ waves. The Ca2+ response depends on the prestress intercellular Ca2+ activity and not on the magnitude or duration of the mechanical stimulation applied. Mechanically induced intercellular Ca2+ waves rely on IP3R-mediated Ca2+-induced Ca2+ release and propagation through gap junctions. Thus, intercellular Ca2+ waves in developing epithelia may be a consequence of stress dissipation during organ growth.

Tunable electrochemical pH modulation in a microchannel monitored via the proton-coupled electro-oxidation of hydroquinone.

Electrochemistry is a promising tool for microfluidic systems because it is relatively inexpensive, structures are simple to fabricate, and it is straight-forward to interface electronically. While most widely used in microfluidics for chemical detection or as the transduction mechanism for molecular probes, electrochemical methods can also be used to efficiently alter the chemical composition of small (typically <100 nl) microfluidic volumes in a manner that improves or enables subsequent measurements and sample processing steps. Here, solvent (H2O) electrolysis is performed quantitatively at a microchannel Pt band electrode to increase microchannel pH. The change in microchannel pH is simultaneously tracked at a downstream electrode by monitoring changes in the i-V characteristics of the proton-coupled electro-oxidation of hydroquinone, thus providing real-time measurement of the protonated forms of hydroquinone from which the pH can be determined in a straightforward manner. Relative peak heights for protonated and deprotonated hydroquinone forms are in good agreement with expected pH changes by measured electrolysis rates, demonstrating that solvent electrolysis can be used to provide tunable, quantitative pH control within a microchannel.

Redox cycling on recessed ring-disk nanoelectrode arrays in the absence of supporting electrolyte.

In canonical electrochemical experiments, a high-concentration background electrolyte is used, carrying the vast majority of current between macroscopic electrodes, thus minimizing the contribution of electromigration transport of the redox-active species being studied. In contrast, here large current enhancements are achieved in the absence of supporting electrolyte during cyclic voltammetry at a recessed ring-disk nanoelectrode array (RRDE) by taking advantage of the redox cycling effect in combination with ion enrichment and an unshielded ion migration contribution to mass transport. Three distinct transport regimes are observed for the limiting current as a function of the concentration of redox species, Ru(NH3)6(2+/3+), revealed through the strong dependence of ion transport on ionic strength. Behavior at low analyte concentrations is especially interesting. In the absence of supporting electrolyte, ions accumulate in the nanopores, resulting in significantly increased current amplification compared to redox cycling in the presence of supporting electrolyte. Current enhancements as large as 100-fold arising from ion enrichment and ion migration effects add to the ~20-fold enhancement due to redox cycling, producing a total current amplification as large as 2000-fold compared to a single microelectrode of the same total area, making these RRDE arrays interesting for electrochemical processing and analysis.

Recessed ring-disk nanoelectrode arrays integrated in nanofluidic structures for selective electrochemical detection.

Arrays of recessed ring-disk (RRD) electrodes with nanoscale spacing fabricated by multilayer deposition, nanosphere lithography, and multistep reactive ion etching were incorporated into nanofluidic channels. These arrays, which characteristically exhibit redox cycling leading to current amplification during cyclic voltammetry, can selectively analyze electroactive species based on differences in redox reversibility, redox potential, or both. Using Ru(NH3)6(3+) and ascorbic acid (AA) as model reversible and irreversible redox species, the selectivity for electrochemical measurement of Ru(NH3)6(3+) against a background of AA improves from ∼10, for an array operated in a fluidically unconstrained geometry, to ∼70 for an array integrated within nanofluidic channels. RRD arrays were also used for the detection of dopamine in the presence of AA by cyclic voltammetry. A linear response ranging from 100 nM to 1 mM with a detection limit of 20 nM was obtained for dopamine alone without nanofluidic confinement. In nanochannel-confined arrays, AA was depleted by holding the ring electrodes at +0.5 V versus Ag/AgCl, allowing interference-free determination of dopamine at the disk electrodes in the presence of a 100-fold excess of AA. For selective detection of electrochemically reversible interfering species on an RRD array without nanochannel confinement, a ring potential can be chosen such that one species exhibits exclusively cathodic (anodic) current, allowing the other species to be determined from its anodic (cathodic) current. This approach for selective detection is demonstrated in a mixture of Ru(NH3)6(3+) and Fe(CN)6(3-), which have resolved redox potentials. The same principle was successfully applied to differentiate species with overlapping redox potentials, such as dopamine/Fe(CN)6(3-) and ferrocenemethanol/Fe(CN)6(4-).

Redox cycling in nanoscale-recessed ring-disk electrode arrays for enhanced electrochemical sensitivity.

An array of nanoscale-recessed ring-disk electrodes was fabricated using layer-by-layer deposition, nanosphere lithography, and a multistep reactive ion etching process. The resulting device was operated in generator-collector mode by holding the ring electrodes at a constant potential and performing cyclic voltammetry by sweeping the disk potential in Fe(CN)6(3-/4-) solutions. Steady-state response and enhanced (~10×) limiting current were achieved by cycling the redox couple between ring and disk electrodes with high transfer/collection efficiency. The collector (ring) electrode, which is held at a constant potential, exhibits a much smaller charging current than the generator (disk), and it is relatively insensitive to scan rate. A characteristic feature of the nanoscale ring-disk geometry is that the electrochemical reaction occurring at the disk electrodes can be tuned by modulating the potential at the ring electrodes. Measured shifts in Fe(CN)6(3-/4-) concentration profiles were found to be in excellent agreement with finite element method simulations. The main performance metric, the amplification factor, was optimized for arrays containing small diameter pores (r < 250 nm) with minimum electrode spacing and high pore density. Finally, integration of the fabricated array within a nanochannel produced up to 50-fold current amplification as well as enhanced selectivity, demonstrating the compatibility of the device with lab-on-a-chip architectures.

Enhanced mass transport of electroactive species to annular nanoband electrodes embedded in nanocapillary array membranes.

Electroosmotic flow (EOF) is used to enhance the delivery of Fe(CN)(6)(4-)/Fe(CN)(6)(3-) to an annular nanoband electrode embedded in a nanocapillary array membrane, as a route to high efficiency electrochemical conversions. Multilayer Au/polymer/Au/polymer membranes are perforated with 10(2)-10(3) cylindrical nanochannels by focused ion beam (FIB) milling and subsequently sandwiched between two axially separated microchannels, producing a structure in which transport and electron transfer reactions are tightly coupled. The middle Au layer, which contacts the fluid only at the center of each nanochannel, serves as a working electrode to form an array of embedded annular nanoband electrodes (EANEs), at which sufficient overpotential drives highly efficient electrochemical processes. Simultaneously, the electric field established between the EANE and the QRE (>10(3) V cm(-1)) drives electro-osmotic flow (EOF) in the nanochannels, improving reagent delivery rate. EOF is found to enhance the steady-state current by >10× over a comparable structure without convective transport. Similarly, the conversion efficiency is improved by approximately 10-fold compared to a comparable microfluidic structure. Experimental data agree with finite element simulations, further illustrating the unique electrochemical and transport behavior of these nanoscale embedded electrode arrays. Optimizing the present structure may be useful for combinatorial processing of on-chip sample delivery with electrochemical conversion; a proof of concept experiment, involving the generation of dissolved hydrogen in situ via electrolysis, is described.

Electrolysis in nanochannels for in situ reagent generation in confined geometries.

In situ generation of reactive species within confined geometries, such as nanopores or nanochannels is of significant interest in overcoming mass transport limitations in chemical reactivity. Solvent electrolysis is a simple process that can readily be coupled to nanochannels for the electrochemical generation of reactive species, such as H(2). Here the production of hydrogen-rich liquid volumes within nanofluidic structures, without bubble nucleation or nanochannel occlusion, is explored both experimentally and by modeling. Devices comprised of multiple horizontal nanochannels intersecting planar working and quasi-reference electrodes were constructed and used to study the effects of confinement and reduced working volume on the electrochemical reduction of H(2)O to H(2) and OH(-). H(2) production in the nanochannel-embedded electrode reactor output was monitored by fluorescence emission of fluorescein, which exhibits a pH-dependent emission intensity. Initially, the fluorescein solution was buffered to pH 6.0 prior to stepping the potential cathodic of E(0)' for the generation of OH(-) and H(2). Because the electrochemical products are obtained in a 2:1 stoichiometry, local measurements of pH during and after the cathodic potential steps can be converted into H(2) production rates. Independent experimental estimates of the local H(2) concentration were then obtained from the spatiotemporal fluorescence behavior and current measurements, and these were compared with finite element simulations accounting for electrolysis and subsequent convection and diffusion within the confined geometry. Local dissolved H(2) concentrations were correlated to partial pressures through Henry's Law and values as large as 8.3 atm were obtained at the most negative potential steps. The downstream availability of electrolytically produced H(2) in nanochannels is evaluated in terms of its possible use as a downstream reducing reagent. The results obtained here indicate that H(2) can easily reach saturation concentrations at modest overpotentials.