Bronchiolitis Simulation Module in the Pediatric Preclerkship Educational Exercises (PRECEDE) Curriculum.

Introduction: Acute bronchiolitis is a viral infection infecting 90% of children under the age of 2 years, with approximately 200,000 deaths per year. The current standard of care remains largely respiratory support and prevention. Therefore, understanding how to assess and escalate respiratory supportive care is paramount for health care providers taking care of children. Methods: We used a high-fidelity simulator to simulate an infant with progressing respiratory distress in the setting of acute bronchiolitis. The participants were pediatric clerkship medical students during their preclerkship educational exercises (PRECEDE). The students were asked to evaluate and treat the simulated patient. After debriefing, the students repeated the simulation. We assessed both performances via a weighted checklist specifically developed for this case to measure team performance. Students also completed an overall course evaluation. Results: Ninety out of 121 pediatric clerkship students were enrolled. Performance improved from 57% to 86% ( p < .05). Donning appropriate personal protection equipment was the most missed item both pre- and postdebriefing. Overall, the course was well liked and received. Participants requested more simulation opportunities within PRECEDE as well as a summary document to reinforce learning. Discussion: Pediatric clerkship students improved their performance managing progressing respiratory distress due to acute bronchiolitis via a performance-based assessment tool with sound validity evidence. Improvements going forward include improving faculty diversity and offering more simulation opportunities.

Diabetic ketoacidosis after the treatment of anaphylaxis.

Summary: Anaphylaxis is a rapidly progressive potentially lethal condition, and epinephrine is the most crucial medication in its treatment. In this study, we present a case of diabetic ketoacidosis in a young woman that was precipitated by the administration of epinephrine to treat anaphylaxis. This patient had diabetes mellitus and poor glycemic control and developed ketoacidosis despite having evidence of ongoing endogenous insulin production and having been treated with exogenous long-acting insulin less than 24 h prior to the event. This is a rare, serious, adverse side effect of life-saving medication. This report demonstrates that the risk of diabetic ketoacidosis should be considered when administering epinephrine to patients with diabetes, even in the absence of complete insulin deficiency. Learning points: Epinephrine directly suppresses insulin secretion, stimulates lipolysis, and causes ketone body generation. High-dose catecholamine administration can cause unexpected diabetic ketoacidosis in patients with risk factors. Early administration of insulin may not protect patients from developing ketoacidosis in the setting of high-dose catecholamine administration.

The Structured Oral Examination: A Method to Improve Formative Assessment of Fellows in Pediatric Endocrinology.

OBJECTIVE: A structured oral exam (SOE) can be utilized as a formative assessment to provide high-quality formative feedback to trainees, but has not been adequately studied in graduate medical education. We obtained fellow and faculty perspectives on: 1) educational effectiveness, 2) feasibility/acceptability, and 3) time/cost of a SOE for formative feedback. METHODS: Four pediatric endocrinology cases were developed and peer-reviewed to generate a SOE. The exam was administered by faculty to pediatric endocrinology fellows individually, with feedback after each case. Fellow/faculty perspectives of the SOE were obtained through a questionnaire. Qualitative thematic analysis was utilized to analyze written comments generated by faculty and fellows. RESULTS: Seven of 10 pediatric endocrinology fellowship programs and all 18 fellows within those programs agreed to participate. Thematic analysis of fellow and faculty comments resulted in 5 perceived advantages of the SOE: 1) improved identification of clinically relevant knowledge deficits, 2) improved assessment of clinical reasoning, 3) immediate feedback/teaching, 4) assurance of adequate teaching/assessment of uncommon cases, and 5) more clinically relevant assessment. Mean time to administer one case was 15.8 minutes (2.0) and was mentioned as a potential barrier to implementation. Almost all fellows (17/18, 94%) and faculty (6/7, 86%) would recommend or would most likely recommend implementation of the SOE into their curriculum. CONCLUSIONS: The SOE utilized for formative feedback was perceived by fellows and faculty to have several educational advantages over current assessments and high acceptability. Objective educational advantages should be assessed on future studies of the SOE.

Otitis Media Module in the Pediatric Preclerkship Educational Exercises (PRECEDE) Curriculum.

Introduction: The Johns Hopkins Pediatrics Clerkship developed the PRECEDE (preclerkship educational exercises) curriculum with the primary goal of offering students formative instruction in essential pediatric clinical skills to prepare them for their clerkship. PRECEDE sessions occur at the beginning of each basic clerkship for new clinical clerkship students. The otitis media module is one in a series of modules presented in the curriculum and consists of a lecture and four short skills-development stations, each with a faculty facilitator. Methods: This 2-hour module began with a 1-hour didactic overview of otitis media. Medical students were divided into three groups. One group learned about writing prescriptions via two otitis media clinical vignettes. Another group explored visualization and diagnosis of otitis media via video. The last student group was subdivided and learned proper techniques for positioning and restraining pediatric patients during otoscopic exams and the psychomotor skills for performing otoscopic examinations, including pneumatic otoscopy. Student groups rotated through all four activity stations. Students were guided through discussion to develop interpretation, diagnostic, and treatment skills for acute otitis media. Results: Between 2010 and 2012, 254 third- and fourth-year medical students participated in this module. When asked to evaluate overall quality, 86% of learners rated the module as excellent, and 14% rated it as good. Discussion: By establishing these important skills, students may be better equipped to develop appropriate otitis media assessments, diagnoses, and care plans for patients and to use otitis media as a platform for broad education in other essential pediatric skills.

Growth Module in the Pediatric Preclerkship Educational Exercises (PRECEDE) Curriculum.

Introduction: The Johns Hopkins Pediatrics Clerkship developed this growth module as part of the PRECEDE (preclerkship educational exercises) curriculum, with the primary goal of providing students with experiential, explicit, and standardized instruction in essential pediatric clinical skills to better prepare them to utilize these skills during their clerkship. Methods: This 2-hour growth module begins with a 45-minute didactic overview of growth, including discussion of normal growth, normal variants of growth, and disorders that affect growth, and contains interactive elements to engage the students. Students then divide into groups of four to six, each with a faculty facilitator to work through three cases in a guided discussion to explore specific aspects of growth that may be encountered in a pediatric evaluation. Results: In a survey of 238 students, 97-100% agreed or strongly agreed with eight positive assessments of the module. Likewise, 79% of students rated the module as excellent, the remainder rating the module as good. Discussion: From the perspectives of students and instructors, the implementation of this new module was very successful in its delivery of educational content. These cases were designed to give the students experience in plotting growth parameters against normative data and to gain familiarity with pediatric growth curves in order to identify growth abnormalities. The cases also aimed to reinforce the importance of using growth data in pediatric patients in order to both generate a differential diagnosis for a growth disorder and to modify a differential diagnosis generated by a chief complaint based on growth data.

Dexmedetomidine infusion associated with transient adrenal insufficiency in a pediatric patient: a case report.

Dexmedetomidine is a highly selective α 2-adrenoceptor agonist used for sedation due to its anxiolytic and analgesic properties without respiratory compromise. Due to its structural similarity to etomidate, there has been concern that dexmedetomidine may cause adrenal insufficiency. This concern was initially supported by animal studies, but subsequent human studies demonstrated mixed results. We describe the case of transient adrenal insufficiency in a 1-year-old male who presented with 24% total body surface 2nd degree burns. He required sedation with a prolonged, high-dose dexmedetomidine infusion with a peak infusion dose of 2.7 mcg/kg/hr and duration of 6.5 days. The patient developed lethargy and hypotension four days after discontinuation of his infusion. He had a random cortisol level which was low at 0.4 mcg/dL, and the concern for adrenal suppression was confirmed with an ACTH stimulation test with the baseline cortisol of 0.4 mcg/dL and inappropriate 60 minute post-ACTH stimulation cortisol of 7.8 mcg/dL. While further studies will be needed to clarify the risk of adrenal suppression secondary to dexmedetomidine, this case suggests that caution should be taken when administering dexmedetomidine to pediatric patients and highlights the need for future studies to look at appropriate dosing and duration of dexmedetomidine infusions.

Electron-mediated ferromagnetic behavior in CoO/ZnO multilayers.

CoO/Al-doped ZnO (AZO) multilayers exhibit ferromagnetism up to ~300 K. The magnetic behavior oscillates with odd vs even number of Co layers in the insulating antiferromagnetic CoO and (separately) with the thickness of the AZO layers and vanishes if AZO is replaced by intrinsic ZnO. Magnetization is due to uncompensated (111) ferromagnetic planes of insulating CoO for odd numbers of atomic planes per layer that are coupled together via RKKY exchange mediated by electron carriers in the nonmagnetic AZO layers. The period of the oscillation with AZO thickness qualitatively matches the Fermi wave vector calculated from the carrier concentration measured by ordinary Hall effect. Magnetic polarization of the AZO carriers is confirmed via an anomalous Hall effect that is proportional to the magnetization.

Fe spin reorientation across the metamagnetic transition in strained FeRh thin films.

A spin reorientation accompanying the temperature-induced antiferromagnetic (AFM) to ferromagnetic (FM) phase transition is reported in strained epitaxial FeRh thin films. (57)Fe conversion electron Mössbauer spectrometry showed that the Fe moments have different orientations in FeRh grown on thick single-crystalline MgO and in FeRh grown on ion-beam-assist-deposited (IBAD) MgO. It was also observed, in both samples, that the Fe moments switch orientations at the AFM to FM phase transition. Perpendicular anisotropy was evidenced in the AFM phase of the film grown on IBAD MgO and in the FM phase of that grown on regular MgO. Density-functional theory calculations enabled this spin-reorientation transition to be accurately reproduced for both FeRh films across the AFM-FM phase transition and show that these results are due to differences in strain.

Thermodynamic measurements of Fe-Rh alloys.

FeRh undergoes an unusual antiferromagnetic-to-ferromagnetic (AFM-FM) transition just above room temperature (T(AFM>FM)) that can be tuned or even completely suppressed with small changes in composition. The underlying temperature-dependent entropy difference between the competing AFM and FM states that drives this transition is measured by specific heat as a function of temperature from 2 to 380 K on two nearly equiatomic epitaxial Fe-Rh films, one with a ferromagnetic ground state (Fe-rich) and the other with an antiferromagnetic ground state (Rh-rich). The FM state shows an excess heat capacity near 100 K associated with magnetic excitations that are not present in the AFM state. The integrated entropy and enthalpy differences between the two alloys up to T(AFM>FM) agree with the previously measured entropy of the transition (ΔS = 17 ± 3 J/kg/K) and yield a T=0 energy difference of 3.4 J/g, consistent with literature calculations and experimental data; this agreement supports the use of the Fe-rich FM sample as a proxy for the (unstable) FM state of the AFM Rh-rich sample. From the low-temperature specific heat, along with sound velocity and photoemission measurements, the lattice contribution to the difference (ΔS(latt) = -33 ± 9 J/kg/K) and electronic contribution (ΔS(el) = 8 ± 1 J/kg/K) to the difference in entropy are calculated, from which the excess heat capacity in the FM phase and the resulting entropy difference are shown to be dominated by magnetic fluctuations (ΔS(mag) = 43 ± 9 J/kg/K). The excess magnetic heat capacity is dominated by the magnetic heat capacity of the FM phase, which can be fit to a Schottky-like anomaly with an energy splitting of 16 ± 1 meV and a multiplicity of 1 per unit cell.

Heat transfer simulation and thermal measurements of microfabricated x-ray transparent heater stages.

A microfabricated amorphous silicon nitride membrane-based nanocalorimeter is proposed to be suitable for an x-ray transparent sample platform with low power heating and built-in temperature sensing. In this work, thermal characterization in both air and vacuum are analyzed experimentally and via simulation. Infrared microscopy and thermoreflectance microscopy are used for thermal imaging of the sample area in air. While a reasonably large isothermal area is found on the sample area, the temperature homogeneity of the entire sample area is low, limiting use of the device as a heater stage in air or other gases. A simulation model that includes conduction, as well as radiation and convection heat loss, is presented with radiation and convection parameters determined experimentally. Simulated temperature distributions show that the homogeneity can be improved by using a thicker thermal conduction layer or reducing the pressure of the gas in the environment but neither are good solutions for the proposed use. A new simple design that has improved temperature homogeneity and a larger isothermal area while maintaining a thin thermal conduction layer is proposed and fabricated. This new design enables applications in transmission x-ray microscopes and spectroscopy setups at atmospheric pressure.

Calorimetry of epitaxial thin films.

Thin film growth allows for the manipulation of material on the nanoscale, making possible the creation of metastable phases not seen in the bulk. Heat capacity provides a direct way of measuring thermodynamic properties of these new materials, but traditional bulk calorimetric techniques are inappropriate for such a small amount of material. Microcalorimetry and nanocalorimetry techniques exist for the measurements of thin films but rely on an amorphous membrane platform, limiting the types of films which can be measured. In the current work, ion-beam-assisted deposition is used to provide a biaxially oriented MgO template on a suspended membrane microcalorimeter in order to measure the specific heat of epitaxial thin films. Synchrotron x-ray diffraction showed the biaxial order of the MgO template. X-ray diffraction was also used to prove the high quality of epitaxy of a film grown onto this MgO template. The contribution of the MgO layer to the total heat capacity was measured to be just 6.5% of the total addenda contribution. The heat capacity of a Fe(.49)Rh(.51) film grown epitaxially onto the device was measured, comparing favorably to literature data on bulk crystals. This shows the viability of the MgO∕SiN(x)-membrane-based microcalorimeter as a way of measuring the thermodynamic properties of epitaxial thin films.

Cyclophosphamide for rapid-onset obesity, hypothalamic dysfunction, hypoventilation, and autonomic dysregulation syndrome.

Patients with rapid-onset obesity, hypothalamic dysfunction, hypoventilation, autonomic dysregulation, and neural crest tumor syndrome have poor long-term outcomes. We report a patient who was treated successfully with high-dose cyclophosphamide immunoablation. This experience offers a novel therapeutic approach and an indirect insight into the underlying pathogenesis of this syndrome.

Type 2 diabetes mellitus in children and adolescents.

The rising prevalence of obesity in the United States has resulted in an increased incidence of T2DM in children and adolescents. T2DM now accounts for up to 45% of new cases of diabetes in the pediatric population. Many new medications have been developed for the treatment of T2DM, although few have been investigated in children. Although we have learned much in the past decade, more knowledge is needed regarding the unique aspects of T2DM in pediatric patients to optimize the prevention and treatment of this disease in children and adolescents.

Management of diabetic ketoacidosis in children and adolescents.

* Based on some research evidence, DKA is a significant contributor to morbidity and mortality in children who have type 1 diabetes, and cerebral edema is responsible for most of the deaths during DKA in children. (Dunger, 2004). * Based on strong research evidence, treatment of DKA requires replacement of water and electrolytes and correction of the insulin deficiency. (Dunger, 2004). * Based on some research data and consensus opinion, after providing initial volume expansion (if needed), fluid resuscitation of children who have DKA should be calculated to rehydrate evenly over at least 48 hours. Initial fluid resuscitation should be with an isotonic solution; subsequent fluid management should be with a solution that has a tonicity of at least 0.45% saline. (Dunger, 2004). * Based on strong research evidence, insulin treatment for DKA should begin at a dose of 0.1 units/kg per hour and generally should remain at or above this level until the ketoacidosis is resolved. (Dunger, 2004). * Based on some research evidence, risk factors for the development of cerebral edema during treatment of DKA include the severity of acidosis, greater hypocapnia (after adjusting for the degree of acidosis), higher blood urea nitrogen concentration at presentation, and treatment with bicarbonate. (Dunger, 2004; Glaser, 2002).

Thermodynamic measurements of submilligram bulk samples using a membrane-based "calorimeter on a chip".

Calorimetry offers a direct measurement of thermodynamic properties of materials, including information on the energetics of phase transitions. Many materials can only be prepared in thin film or small crystal (submilligram) form, negating the use of traditional bulk techniques. The use of micromachined, membrane-based calorimeters for submilligram bulk samples is detailed here. Numerical simulations of the heat flow for this use have been performed. These simulations describe the limits to which this calorimetric technique can be applied to the realm of small crystals (1-1000 microg). Experimental results confirm the feasibility of this application over a temperature range from 2 to 300 K. Limits on sample thermal conductivity as it relates to the application of the lumped and distributed tau 2 models are explored. For a typical sample size, the simulations yield 2.5% absolute accuracy for the heat capacity of a sample with thermal conductivity as low as 2 x 10(-5) W/cm K at 20 K, assuming a strong thermal link to the device. Silver paint is used to attach (both thermally and physically) the small samples; its heat capacity and reproducibility are discussed. Measurements taken of a submilligram single crystal of cobalt oxide (CoO) compare favorably to the results of a bulk calorimetric technique on a larger sample.

Adipocyte gene expression is altered in formerly obese mice and as a function of diet composition.

In the development of obesity, the source of excess energy may influence appetite and metabolism. To determine the effects of differences in diet composition in obesity, mice were fed either a high-carbohydrate diet (HC; 10% fat energy) or a high-fat energy-restricted diet (HFR; 60% fat energy) over 18 wk in weight-matched groups of mice. To identify obesity-associated genes with persistently altered expression following weight reduction, mice were fed either a standard low-fat diet (LF; 10% fat energy), an unrestricted high-fat diet (HF; 60% fat energy), or a HF diet followed by weight reduction (WR). Mice fed a HF diet had significantly greater gonadal fat mass and higher whole blood glucose concentrations than mice fed an HC diet. Of the mice fed a high-fat diet, total body weight and serum insulin concentrations were greater in HF than in HFR. Microarray analysis revealed that HF vs. HC feeding resulted in global differences in adipocyte gene expression patterns. Although we identified genes whose expression was altered in both moderately and severely obese mice, there were also a large number of genes with altered expression only in severe obesity. Formerly obese, WR mice did not differ significantly from lean controls in total body weight or physiological measures. However, microarray analysis revealed distinctly different patterns of adipocyte gene expression. Furthermore, there were 398 genes with altered expression in HF mice that persisted in WR mice. Genes with persistently altered expression following obesity may play a role in rebound weight gain following weight reduction.

Repression of GLUT4 expression by the endoplasmic reticulum stress response in 3T3-L1 adipocytes.

Expression of GLUT4 is decreased in adipocytes in obesity and type 2 diabetes, contributing to the insulin resistance of these states. Recent investigations suggest a role for activation of the ER stress response in the pathophysiology of type 2 diabetes. We investigated activation of the ER stress response in 3T3-L1 adipocytes. We show that activation of the ER stress response decreased GLUT4 expression at the level of gene transcription. Activation of the ER stress response also increased the expression of CHOP10, an inhibitor of the activity and expression of C/EBPalpha. As expected, activation of the ER stress response decreased expression of C/EBPalpha, an activator of GLUT4 expression, providing a mechanism to account for the repression of GLUT4 by ER stress activation. Our studies identify repression of GLUT4 expression as another potential mechanism for obesity-induced activation of the ER stress response to contribute to the insulin resistance of obesity.

Application of calorimetry on a chip to high-pressure materials.

Silicon micromachined calorimeters ("calorimeter on a chip") are used to measure heat capacities and phase transition enthalpies for thin film, single crystal, and powder samples (5-500 mug). The technology is thus compatible with the small samples produced in multianvil and large diamond anvil cells. Techniques for handling small samples and attaching them to the calorimetric devices have been developed. Initial data illustrate application to CoO and to Fe(2)SiO(4) olivine and spinel, a quenched high pressure phase metastable at ambient conditions. The calorimetric entropy of the olivine-spinel transition in Fe(2)SiO(4) (-16 +/- 5 J/mol.K) is in good agreement with that calculated from phase equilibrium data (-14 +/- 3 J/mol.K). A magnetic transition in iron silicate spinel, detected previously by Mossbauer spectroscopy, is seen in the calorimetric signal.