Anaphylaxis Triggers and Treatments by Grade Level and Staff Training: Findings from the EPIPEN4SCHOOLS Pilot Survey.

This pilot survey was designed to evaluate the characteristics of anaphylactic events and epinephrine autoinjector (EAI) use in children in U.S. schools. A cross-sectional, web-based, pilot survey of schools participating in the EPIPEN4SCHOOLS® program (Mylan Specialty L.P., Canonsburg, PA) assessed characteristics of anaphylactic events and EAI use during the 2013-2014 academic year. Respondents reported 757 anaphylactic events experienced by students; student grade level was noted for 724 events. Of these events, 32.3% (234/724) were experienced by students in grade school, 18.6% (135/724) by students in middle school, and 49.0% (355/724) by students in high school. Frequency of food-related triggers was consistently high across grade levels. However, many events experienced by students in high school (22.3%, 79/355), middle school (15.0%, 20/135), and grade school (14.1%, 33/234) had an unknown trigger. In 36.0% of schools (2008/5579), only the school nurse and select staff received training to recognize anaphylaxis; most staff or all staff received training in 28.9% (1610/5579) and 30.9% (1722/5579) of schools, respectively. In a majority of schools (54.2%, 3003/5544), only the school nurse and select staff were permitted to administer epinephrine, whereas most staff or all staff were permitted to administer epinephrine in 15.8% (876/5544) and 21.9% (1212/5544) of schools, respectively. Risk of anaphylaxis may be particularly high during adolescence, and some students encounter staff members who are untrained in anaphylaxis recognition or management, or both. These findings support the need for continued anaphylaxis training for the protection of all students, staff, and visitors.

EpiPen4Schools pilot survey: Occurrence of anaphylaxis, triggers, and epinephrine administration in a U.S. school setting.

BACKGROUND: Although epinephrine is the treatment of choice for anaphylaxis, it remains underused. OBJECTIVE: This study was designed to describe anaphylactic events and epinephrine autoinjector (EAI) use in U.S. schools enrolled in the EpiPen4Schools program. METHODS: This exploratory, cross-sectional, Web-based survey of 6019 schools that participated in the EpiPen4Schools program assessed anaphylactic events and EAI use at responding schools during the 2013-2014 school year. RESULTS: A total of 919 anaphylactic events were reported in 607 schools. Of the 852 anaphylactic events with data on those who experienced an event, most 88.8% (n = 757) occurred in students, and 21.9% of events (n = 187) occurred in individuals with no known allergies. Of the 851 events with data on EAI use, 74.7% (n = 636) were treated with EAIs and 8.5% (n = 54) received a second epinephrine injection. Of the 204 individuals not treated with an EAI, 77.0% (n = 157) received antihistamines, 12.7% (n = 26) received another treatment, and 8.3% (n = 17) received no treatment. Of the 850 events with data on hospital transport, 79.6% of individuals (n = 677) were transported to the hospital. Common triggers varied seasonally, with food listed most frequently overall (62.5%). CONCLUSION: More than one in ten schools that participated in the EpiPen4Schools survey reported an anaphylactic event. Approximately 25% of individuals with anaphylactic events were not treated with EAIs, and 20.4% of patients were not taken to the hospital after an anaphylactic event. Analysis of these data supports the value of stocking EAIs and of providing continuing education regarding the recognition and proper treatment of anaphylaxis for school personnel.

Effects of millimeter wave irradiation and equivalent thermal heating on the activity of individual neurons in the leech ganglion.

Many of today's radiofrequency-emitting devices in telecommunication, telemedicine, transportation safety, and security/military applications use the millimeter wave (MMW) band (30-300 GHz). To evaluate the biological safety and possible applications of this radiofrequency band for neuroscience and neurology, we have investigated the physiological effects of low-intensity 60-GHz electromagnetic irradiation on individual neurons in the leech midbody ganglia. We applied incident power densities of 1, 2, and 4 mW/cm(2) to the whole ganglion for a period of 1 min while recording the action potential with a standard sharp electrode electrophysiology setup. For comparison, the recognized U.S. safe exposure limit is 1 mW/cm(2) for 6 min. During the exposure to MMWs and gradual bath heating at a rate of 0.04°C/s (2.4°C/min), the ganglionic neurons exhibited similar dose-dependent hyperpolarization of the plasma membrane and decrease in the action potential amplitude. However, narrowing of the action potential half-width during MMW irradiation at 4 mW/cm(2) was 5 times more pronounced compared with that during equivalent bath heating of 0.6°C. Even more dramatic difference in the effects of MMW irradiation and bath heating was noted in the firing rate, which was suppressed at all applied MMW power densities and increased in a dose-dependent manner during gradual bath heating. The mechanism of enhanced narrowing of action potentials and suppressed firing by MMW irradiation, compared with that by gradual bath heating, is hypothesized to involve specific coupling of MMW energy with the neuronal plasma membrane.

Thermal mechanisms of millimeter wave stimulation of excitable cells.

Interactions between millimeter waves (MMWs) and biological systems have received increasing attention due to the growing use of MMW radiation in technologies ranging from experimental medical devices to telecommunications and airport security. Studies have shown that MMW exposure alters cellular function, especially in neurons and muscles. However, the biophysical mechanisms underlying such effects are still poorly understood. Due to the high aqueous absorbance of MMW, thermal mechanisms are likely. However, nonthermal mechanisms based on resonance effects have also been postulated. We studied MMW stimulation in a simplified preparation comprising Xenopus laevis oocytes expressing proteins that underlie membrane excitability. Using electrophysiological recordings simultaneously with 60 GHz stimulation, we observed changes in the kinetics and activity levels of voltage-gated potassium and sodium channels and a sodium-potassium pump that are consistent with a thermal mechanism. Furthermore, we showed that MMW stimulation significantly increased the action potential firing rate in oocytes coexpressing voltage-gated sodium and potassium channels, as predicted by thermal terms in the Hodgkin-Huxley model of neurons. Our results suggest that MMW stimulation produces significant thermally mediated effects on excitable cells via basic thermodynamic mechanisms that must be taken into account in the study and use of MMW radiation in biological systems.

An RF-powered micro-reactor for the detection of astrobiological target molecules on planetary bodies.

We describe a sample-processing micro-reactor that utilizes 60 GHz RF radiation with approximately 730 mW of output power. The instrument design and performance characterization are described and then illustrated with modeling and experimental studies. The micro-reactor's efficiency on affecting hydrolysis of chemical bonds similar to those within large complex molecules was demonstrated: a disaccharide-sucrose-was hydrolyzed completely under micro-reactor conditions. The products of the micro-reactor-facilitated hydrolysis were analyzed using mass spectroscopy and proton nuclear magnetic resonance analytical techniques.

Modulation of neuronal activity and plasma membrane properties with low-power millimeter waves in organotypic cortical slices.

As millimeter waves (MMWs) are being increasingly used in communications and military applications, their potential effects on biological tissue has become an important issue for scientific inquiry. Specifically, several MMW effects on the whole-nerve activity were reported, but the underlying neuronal changes remain unexplored. This study used slices of cortical tissue to evaluate the MMW effects on individual pyramidal neurons under conditions mimicking their in vivo environment. The applied levels of MMW power are three orders of magnitude below the existing safe limit for human exposure of 1 mW cm(-2). Surprisingly, even at these low power levels, MMWs were able to produce considerable changes in neuronal firing rate and plasma membrane properties. At the power density approaching 1 microW cm(-2), 1 min of MMW exposure reduced the firing rate to one third of the pre-exposure level in four out of eight examined neurons. The width of the action potentials was narrowed by MMW exposure to 17% of the baseline value and the membrane input resistance decreased to 54% of the baseline value across all neurons. These effects were short lasting (2 min or less) and were accompanied by MMW-induced heating of the bath solution at 3 degrees C. Comparison of these results with previously published data on the effects of general bath heating of 10 degrees C indicated that MMW-induced effects cannot be fully attributed to heating and may involve specific MMW absorption by the tissue. Blocking of the intracellular Ca(2+)-mediated signaling did not significantly alter the MMW-induced neuronal responses suggesting that MMWs interacted directly with the neuronal plasma membrane. The presented results constitute the first demonstration of direct real-time monitoring of the impact of MMWs on nervous tissue at a microscopic scale. Implication of these findings for the therapeutic modulation of neuronal excitability is discussed.

Thermal monitoring: Raman spectrometer system for remote measurement of cellular temperature on a microscopic scale.

A simple setup is demonstrated for remote temperature monitoring of water, water-based media, and cells on a microscopic scale. The technique relies on recording changes in the shape of a stretching band of the hydroxyl group in liquid water at 3,100-3,700 cm(-1). Rather than direct measurements in the near-infrared (IR), a simple Raman spectrometer setup is realized. The measured Raman shifts are observed at near optical wavelengths using an inverted microscope with standard objectives in contrast to costly near-IR elements. This allows for simultaneous visible inspection through the same optical path. An inexpensive 671-nm diode pump laser (< 100 mW), standard dichroic and lowpass filters, and a commercial 600-1,000 nm spectrometer complete the instrument. Temperature changes of 1 degrees C are readily distinguished over a range consistent with cellular processes (25-45 degrees C) using integration times below 10 s. Greatly improved sensitivity was obtained by an automated two-peak fitting procedure. When combined with an optical camera, the instrument can be used to monitor changes in cell behavior as a function of temperature without the need for invasive probing. The instrument is very simple to realize, inexpensive compared with traditional Raman spectrometers and IR microscopes, and applicable to a wide range of problems in microthermometry of biological systems. In a first application of its kind, the instrument was used to successfully determine the temperature rise of a cluster of H1299 derived human lung cells adhered to polystyrene and immersed in phosphate-buffered saline (PBS) under exposure of RF millimeter wave radiation (60 GHz, 1.3, 2.6, and 5.2 mW/mm2).

Low-loss terahertz ribbon waveguides.

The submillimeter wave or terahertz (THz) band (1 mm-100 microm) is one of the last unexplored frontiers in the electromagnetic spectrum. A major stumbling block hampering instrument deployment in this frequency regime is the lack of a low-loss guiding structure equivalent to the optical fiber that is so prevalent at the visible wavelengths. The presence of strong inherent vibrational absorption bands in solids and the high skin-depth losses of conductors make the traditional microstripline circuits, conventional dielectric lines, or metallic waveguides, which are common at microwave frequencies, much too lossy to be used in the THz bands. Even the modern surface plasmon polariton waveguides are much too lossy for long-distance transmission in the THz bands. We describe a concept for overcoming this drawback and describe a new family of ultra-low-loss ribbon-based guide structures and matching components for propagating single-mode THz signals. For straight runs this ribbon-based waveguide can provide an attenuation constant that is more than 100 times less than that of a conventional dielectric or metallic waveguide. Problems dealing with efficient coupling of power into and out of the ribbon guide, achieving low-loss bends and branches, and forming THz circuit elements are discussed in detail. One notes that active circuit elements can be integrated directly onto the ribbon structure (when it is made with semiconductor material) and that the absence of metallic structures in the ribbon guide provides the possibility of high-power carrying capability. It thus appears that this ribbon-based dielectric waveguide and associated components can be used as fundamental building blocks for a new generation of ultra-high-speed electronic integrated circuits or THz interconnects.

Carbon nanotube Schottky diodes using Ti-Schottky and Pt-Ohmic contacts for high frequency applications.

We have demonstrated Schottky diodes using semiconducting single-walled nanotubes (s-SWNTs) with titanium Schottky and platinum Ohmic contacts for high-frequency applications. The diodes are fabricated using angled evaporation of dissimilar metal contacts over an s-SWNT. The devices demonstrate rectifying behavior with large reverse bias breakdown voltages of greater than -15 V. To decrease the series resistance, multiple SWNTs are grown in parallel in a single device, and the metallic tubes are burnt-out selectively. At low biases these diodes showed ideality factors in the range of 1.5 to 1.9. Modeling of these diodes as direct detectors at room temperature at 2.5 terahertz (THz) frequency indicates noise equivalent powers (NEP) potentially comparable to that of the state-of-the-art gallium arsenide solid-state Schottky diodes, in the range of 10(-13) W/ radical Hz.