Documented home apnea monitoring: effect on compliance, duration of monitoring, and validation of alarm reporting

The objectives of this study were to: (1) measure patient compliance with monitoring, (2) validate parental reports of alarms at home, (3) examine monitoring duration, and (4) compare documented monitor records with the traditional pneumogram to evaluate patients for monitor discontinuation. During the 1-year period from January through December, 1992, 114 infants were followed up with documented monitoring. Simultaneously, 113 infants were followed up with conventional monitors. Infants were premature, or victims of apparent life-threatening episodes (ALTE), or siblings of SIDS victims. Monitors recorded all episodes of apnea greater than 15 seconds and bradycardia less than 80 beats per minute. All families were contacted biweekly by telephone. Downloads were performed at regular intervals. Monitor downloads were compared with simultaneous pneumograms to assess the accuracy of a long-term, intermittent event-recording system versus short-term (6- to 12-hour) continuous recording. All families were highly compliant with the use of home monitoring. Although Caucasian families used the monitors more often than non-Caucasian families, all groups used the monitor > 75% of the time. True episodes were verified in 38% of patients by monitor downloads. Only 7.4% of all recorded events were true events. Of the real events, 51.2% were apneas of 16-20 seconds. No significant differences were found in overall duration of monitoring between documented and nondocumented monitors. In the premature infants, the duration of monitoring was significantly reduced in those infants found to have no true episodes over those with real events at home. Readmission for ALTE was reduced in infants with documented monitors. Premature infants without events were monitored an average of 24 fewer days (P = 0.03). Computerized monitor downloads were found to be equally, if not more, sensitive than pneumograms in evaluating infants for monitor discontinuation. Documented monitoring offers a viable alternative to traditional monitoring and pneumograms in assisting clinicians and families in evaluating their infant's progress. By accurately assessing compliance, distinguishing true from false alarms, and decreasing the need for pneumograms, these devices provide valuable information to clinicians and families.     

HL7, MEDIX and the pursuit of the unified standard

The move toward open systems environments in healthcare computing has gained momentum in recent years. The authors, both deeply involved in the development of standard communication protocols for disparate systems, explain the status of current convergence efforts both here and abroad, with emphasis on HL7 and MEDIX.     

Cyclosporine A Protects Retinal Explants against Hypoxia

The retina is a complex neurological tissue and is extremely sensitive to an insufficient supply of oxygen. Hypoxia plays a major role in several retinal diseases, and often results in the loss of cells that are essential for vision. Cyclosporine A (CsA) is a widely used immunosuppressive drug. Furthermore, treatment with CsA has neuroprotective effects in several neurologic disorders. No data are currently available on the tolerated concentration of CsA when applied to the retina. To reveal the most effective dose, retinal explants from rat eyes were exposed to different CsA concentrations (1–9 µg/mL). Immunohistochemistry with brain-specific homeobox/POU domain protein 3a (Brn3a) and TUNEL staining was performed to determine the percentage of total and apoptotic retinal ganglion cells (RGCs), as well as the responses of micro- and macroglial cells. Furthermore, optical coherence tomography (OCT) scans were performed to measure the changes in retinal thickness, and recordings with multielectrode array (MEA) were performed to evaluate spontaneous RGC spiking. To examine the neuroprotective effects, retinas were subjected to a hypoxic insult by placing them in a nitrogen-streamed hypoxic chamber prior to CsA treatment. In the biocompatibility tests, the different CsA concentrations had no negative effect on RGCs and microglia. Neuroprotective effects after a hypoxic insult on RGCs was demonstrated at a concentration of 9 µg/mL CsA. CsA counteracted the hypoxia-induced loss of RGCs, reduced the percentage of TUNEL⁺ RGCs, and prevented a decrease in retinal thickness. Taken together, the results of this study suggest that CsA can effectively protect RGCs from hypoxia, and the administered concentrations were well tolerated. Further in vivo studies are needed to determine whether local CsA treatment may be a suitable option for hypoxic retinal diseases.     

Safer energetic materials by a nanotechnological approach

Energetic materials - explosives, thermites, populsive powders - are used in a variety of military and civilian applications. Their mechanical and electrostatic sensitivity is high in many cases, which can lead to accidents during handling and transport. These considerations limit the practical use of some energetic materials despite their good performance. For industrial applications, safety is one of the main criteria for selecting energetic materials. The sensitivity has been regarded as an intrinsic property of a substance for a long time. However, in recent years, several approaches to lower the sensitivity of a given substance, using nanotechnology and materials engineering, have been described. This feature article gives an overview over ways to prepare energetic (nano-)materials with a lower sensitivity.     

Styrene-Butadiene Polytelomers for Pressure-Sensitive Applications

Novel styrene-butadiene polymer latex compositions and their utility for pressure-sensitive and other adhesive applications are described. These compositions, termed polytelomers, are based on the concept of synthesising sequentially a low glass transition temperature, high molecular weight (polymeric) fraction, followed by a high glass transition, low molecular weight (telomeric) fraction, in an attempt to simulate the compounding of elastomeric adhesives. Some of the described compositions can exhibit multiphase morphology, having discrete styrene-rich domains surrounded by butadiene rich phase, both of these phases being embedded in a “honeycomb” carboxyl-rich phase. The compositions were characterized by dynamic mechanical spectroscopy and by electron transmission microscopy, as well as by molecular weight distribution and glass transition temperature range data. Examples of adhesive applications are also given.     

Highly Insensitive/Reactive Thermite Prepared from Cr2O3 Nanoparticles

Thermites prepared from nanoparticles are currently the subject of growing interest due to their increased performances compared to classical micrometer‐sized thermites. Here, we studied the combustion behavior of energetic composite composed of Al and chromium (III) oxide (Cr₂O₃) as function of the oxide particle size. Homogeneous composites were prepared by mixing Al nanoparticles (Φ≈50 nm) with Cr₂O₃ micro‐ and nanoparticles (Φ≈20 nm), respectively, in hexane solution. The dried Cr₂O₃/Al composite powders were ignited by using a CO₂ laser beam. The use of nanosized Cr₂O₃ particles incontestably improves the energetic performances of the Al/Cr₂O₃ thermite since the ignition delay time was shortened by a factor 3.5 (16±2 vs 54±4 ms) and the combustion rate (340±10 mm s⁻¹) was significantly accelerated in contrast to those reported until now. Interestingly, the sensitivity to friction of the Al‐based thermites formulated from Cr₂O₃ is two orders of magnitude lower than the thermite prepared from other metal oxide nanoparticles (MnO₂, WO₃). Finally, our study shows that the decrease of Cr₂O₃ particle size has an interesting and beneficial effect on the energetic properties of Cr₂O₃/Al thermites and appears as an alternative to tune the properties of these energetic materials.