Post-market surveillance of consumer products: Framework for adverse event management.

Analysis of spontaneous reports of adverse events is an important source of information that can be used to improve consumer products. Various agencies have adverse event reporting requirements and many companies collect such data directly from consumers. Nonetheless, a universal framework is absent that identifies and evaluates spontaneously reported adverse events, and, most important, assesses the potential association between exposure and adverse events. We are presenting a three-part framework: Phase I - Intake and Documentation of Original Incidents; Phase II - In Depth Review and Follow-up of Phase I Incidents (enhanced, tailored questionnaire); Phase III - Association Assessment. The basis for scoring the strength of association between exposure and adverse events requires assessment of standard factors of association including: temporality; biological, physiological, or pharmacological plausibility; results of de-challenge; results of re-challenge; and consideration of confounding factors. Scores tied to the answers to these questions are totaled for each incident to determine the strength of association between exposure and reported adverse event. We propose that consumer product companies come together to adopt such an association assessment framework to improve adverse event management, obtain maximum value from the data obtained, and use the knowledge derived to improve overall product safety for consumers.

The Feynman propagator from a single path.

We show that it is possible to construct the Feynman propagator for a free particle in one dimension, without quantization, from a single continuous space-time path.

Fractura de pierna: enclavado endomedular in situ con clavo Kuntscher abulonado

Se realizó un estudio sobre 32 fracturas de pierna cerradas o expuestas grado 1 de Gustillo tratadas mediante enclavado endomedular con clavos Kuntscher trebolados de 9 mm sin fresado, a cielo cerrado, bloqueado in situ y sin intensificador de imágenes. Se logró reducción a cielo cerrado en el 87 por ciento de los casos y consolidación en el 100 por ciento con 78 por ciento de buenos resultados. Dentro de las complicaciones, la ruptura del clavo se presentó en el 3 por ciento de los pacientes y la ruptura del tornillo de bloqueo, en el 18 por ciento. Se concluye que la técnica propuesta presenta más complicaciones que los métodos de nueva generación, pero representa una alternativa válida para pacientes con escasos recursos o en medios donde no se cuente con intensificador de imágenes

Information loss in the continuum limit and Schrödinger's equation in an electromagnetic field.

Since the time of Einstein's work on Brownian motion it has been known that random walks provide a microscopic model for the diffusion equation. Less well known is the fact that some instances of Schrödinger's equation occur naturally in the description of the statistics of these same walks and thus have classical contexts which are distinct from their usual association with quantum mechanics. An interesting feature of these models is the fact that the information which relates Schrödinger's equation to its classical context is not contained in the partial differential equation itself, but is lost in the continuum limit which gives rise to the equation. In this article we illustrate the above by showing that Schrödinger's equation for a particle in an electromagnetic field in 1 + 1 dimension occurs as a continuum limit of a description of a classical system of point particles on a lattice. The derivation shows that the information lost in the continuum limit is necessary to link the mathematics to the physical context of the equation.

Fractura de pierna: enclavado endomedular in situ con clavo Kuntscher abulonado

Se realizó un estudio sobre 32 fracturas de pierna cerradas o expuestas grado 1 de Gustillo tratadas mediante enclavado endomedular con clavos Kuntscher trebolados de 9 mm sin fresado, a cielo cerrado, bloqueado in situ y sin intensificador de imágenes. Se logró reducción a cielo cerrado en el 87 por ciento de los casos y consolidación en el 100 por ciento con 78 por ciento de buenos resultados. Dentro de las complicaciones, la ruptura del clavo se presentó en el 3 por ciento de los pacientes y la ruptura del tornillo de bloqueo, en el 18 por ciento. Se concluye que la técnica propuesta presenta más complicaciones que los métodos de nueva generación, pero representa una alternativa válida para pacientes con escasos recursos o en medios donde no se cuente con intensificador de imágenes

Fatal bupropion overdose.

BACKGROUND: Bupropion is a unique monocyclic antidepressant that has been known to cause seizures in high therapeutic doses and in acute overdoses. Death due to ingestion, however, is a rare occurrence. CASE REPORT: We report a case of a 26-year-old man who ingested 23 g bupropion, developed seizures and hypoxia, and presented in cardiac arrest. The patient was resuscitated in the emergency department, but died 4 d after supportive intensive care. CONCLUSIONS: Bupropion overdose may lead to recurrent seizures, hypoxia and death. Aggressive management of severe bupropion overdose is recommended.

Comparison of neural networks and regression-based methods for temperature retrievals.

Two methods for performing clear-air temperature retrievals from simulated radiances for the Atmospheric Infrared Sounder are investigated. Neural networks are compared with a well-known linear method in which regression is performed after a change of bases. With large channel sets, both methods can rapidly perform clear-air retrievals over a variety of climactic conditions with an overall RMS error of less than 1 K. The Jacobian of the neural network is compared with the Jacobian (the regression coefficients) of the linear method, revealing a more fine-scale variation than expected from the underlying physics, particularly for the neural net. Some pragmatic information concerning the application ofneural nets to retrieval problems is also included.

Advances in high-Q piezoelectric resonator materials and devices.

In order to compare piezoelectric materials and devices, an intrinsic parameter, the motional time constant tau(1)/sup (m/)=(omega/sub m/Q/sub m/)(-1) for a particular mode m is employed. The use of tau(1)/sup (m/) follows from the accommodation of acoustic loss in the elastic compliance/stiffness and the establishment of material coefficients that are elements of viscosity matrices. Alternative and fully equivalent definitions of tau(1) are given based on the RC time constant derived from the equivalent circuit representation of a crystal resonator, acoustic attenuation, logarithmic decrement, and viscosity or damping. For quartz devices, the variation of tau(1): for any simple thickness mode, for the Y'X shear mode for rotated Y-cuts, and with diameter-thickness ratio for AT-cuts is discussed. Other factors such as mounting loss and loss caused by crystal inhomogeneities (dislocations, defect positions in the resonator, and impurity migration under vibrational stress) are briefly considered with quartz devices as the model. Some new piezoelectric materials/material constants/devices are reviewed and their motional time constants are compared. A physical parameter, composed of acoustic velocity, piezoelectric coupling, and tau(1) is identified which aids in understanding the maximum frequency limitations of plate resonators.

Chagas disease in north-west Argentina: risk of domestic reinfestation by Triatoma infestans after a single community-wide application of deltamethrin.

The risk of domestic reinfestation by Triatoma infestans after a single community-wide application of delta-methrin (2.5% suspension concentrate at 25 mg active ingredient/m2) was studied in Amamá, north-west Argentina, where no insecticide spraying had been done by official control services. The percentage of infested houses fell from 88% before spraying in 1985 to nil during the 6 months after spraying, and thereafter increased from 5% in 1986 to 96% before a second treatment in 1992, fitting closely to a logistic model (r2 = 0.997). Significant risk factors associated with domestic reinfestation determined from stepwise logistic regression and one-factor analysis were the density of T. infestans in bedrooms just before spraying and the surface structure of indoor walls. Peak densities of bugs in 1988-1989 significantly differed between levels of both risk factors. Our study suggests the existence of stable determinants of infestation linked to the household which, in the absence of effective control measures, would also determine the speed of house recolonization and the ensuing bug densities. Plastering of mud walls before application of insecticides to all domestic and peridomestic structures is supported by the study.

Thermoelastic coefficients of alpha quartz.

Experimental measurements of alpha quartz thermal expansion as reported in the literature have been critically analyzed. A recommended set of best measured values over the temperature range -50 degrees C to +150 degrees C have been determined, as have values for the coefficient of thermal linear expansion (CTE) and the thermoelastic coefficients. The impact of using the coefficients on determinations of quartz material temperature coefficients and on the calculation of temperature coefficients of frequency for the case of the AT-cut is discussed.

Electrode-induced nonuniformities in the sweeping of alpha quartz.

Infrared absorption and scanning electron microscopic techniques show that color-center and/or electrode-metal introduction into quartz is influenced by the porosity of evaporated metal electrodes. Thermal-stress relief of electrode-metal films, during sweeping, normally causes porosity. If the porosity is extensive, H introduction predominates and color-center and electrode-metal introduction mechanisms are suppressed. Samples swept with evaporated Au/Cr electrodes relying on thermal stress-induced porosity sometimes displayed these sweeping nonuniformities. Nonuniformities were not found when samples were swept using evaporated Au-Cr electrodes containing periodic stripe openings. Uniform sweeping was also obtained using magnetron-sputtered amorphous Y-Ba-Cu-O films.

Spurious surface finish improvement of the infrared extinction coefficient of alpha quartz.

Infrared extinction coefficients obtained using quartz samples lapped with a 3 mum abrasive compound were found to be much smaller than anticipated. The improvement in extinction coefficient is traceable to the irregular surface finish. To demonstrate this improvement, polished quartz samples were evaluated and compared to evaluations after lapping the same sample with 3 mum and 12 mum abrasives. In one sample, a 3 mum finish resulted in an almost 30% improvement in the extinction coefficient evaluated at 3500 cm(-1). Lapping of the sample to a 12 mum finish resulted in an almost 90% improvement. These improvements in alpha correspond to improvements in Q(IR ) (3500) from 2.58 million (polished) to 3.03 million (3 mu) to 4.71 million (12 mum). The improvement is caused by wavelength dependent transmission losses due to surface irregularities. The surface transmission losses can be reduced by polishing the optical surfaces or by applying index matching fluids to 3 mum lapped surfaces.

Electrode effects in the sweeping of alpha quartz.

Experimental observations are described in the air-sweeping of alpha-quartz that reveal the introduction of hydrogen. Porous electrodes facilitate the indiffusion of hydrogen. By contrast, the use of thick, nonporous, strongly adherent Au/Cr electrodes causes a color-center front to advance from anode to cathode. Evidence is presented that indicates that: (1) color centers form beneath nonporous portions of the anode that correlate with the formation of Cr(2)O(3) on the metal surface and Cr-silicides at the metal-quartz interface, and (2) large-diameter clear striae form along the c-axis that correlate with small openings in the anode. These observations suggest that: (1) openings in the anode metallization are required for hydrogen introduction; (2) the electrochemical charge-transfer reaction, leading to hydrogen introduction, occurs at the gas-electrode-quartz boundary and spreads laterally by interfacial diffusion of hydrogen species; and (3) color centers form through the suppression of interfacial H-diffusion. Additionally, electrode-surface damage and high electric fields can result in undesirable electrode-metal indiffusion.

First-pass uptake of verapamil, diazepam, and thiopental in the human lung.

The first-pass uptake of verapamil, diazepam, and thiopental in the human lung was determined using multiple-indicator dilution techniques. These three drugs represent lipid-soluble agents that differ in their ionic characteristics at physiological pH. Verapamil, a basic lipophilic amine, underwent significant uptake, with 50% of the drug accumulating in lung tissue during the first pass. With diazepam, a nonbasic lipophilic amine, there was 30% uptake during the first pass through the human lung--significantly less than that observed with verapamil. With thiopental, an acidic lipophilic barbiturate, only 14% of the injected drug accumulated in the lung during the first pass. Taken together, these data are consistent with observations from animal studies, which indicate that extensive pulmonary uptake is greater with basic amine drugs that are moderately to highly lipid-soluble. Also, the relatively high first-pass uptake of verapamil in the human lung suggests a quantitatively significant role of this nonrespiratory function of the lung in the early pharmacokinetics of intravenous verapamil.

A new tool for continuous detection of the presence of triatomine bugs, vectors of Chagas disease, in rural households

Ante la necesidad de contar con un dispositivo sencillo pero sensible para detectar triatominos domiciliarios y como parte del conjunto de actividades de vigilancia de la transmisión de la Enfermedad de Chagas en áreas rurales, mediante investigaciones realizadas en el INDIECH, se desarrolló un nuevo tipo de caja de cartulina denominado sensor María. La caja de cartulina rígida de 40x22x2cm, está abierta en ambos costados y en su extremo inferior, para permitir la libre entrada y salida de las vinchucas. En su interior contiene una cartulina blanda absorbente plegada en acordeón que posee una serie de orificios verticales a través de los cuales los insectos pueden desplazarse. El sensor María fue instalado dentro de los dormitorios de 38 viviendas en Amamá, Departamento de Moreno, y en 19 casas de Gramilla, Departamento de Gramilla, ambos de la provincia de Santiago del Estero. Estas localidadess no habían sido rociadas nunca con insecticidas, pero en Gramilla la densidad de vinchucas era inferior a la correspondiente a Amamá. En ambas localidades se comparó la sensibilidad de los sensores María para detectar la presencia de vinchucas en las casas, con la colecta manual de insectos por el método hora/hombre, correspondiente a un esfuerzo de 1 hora/hombre/casa utilizando movilizadores químicos. Dicha colecta manual se realizó al final de cada experimento que se prolongó por 30 días en Amamá y por 90 días en Gramilla. En Amamá los sensores María detectaron un 71% de casas infestadas mientras que por captura manual se registró un 79% de casas positivas. Los sensores detectaron el 90% de las viviendas de alta infestación por la presencia de evidencias (exuvias, huevos, rastros de materia fecal) y el 55% de ellas por la presencia de vinchucas vivas. En las casas de baja infestación, un 75% de los dormitorios tenían evidencias en los sensores y en un 30% de ellas se hallaron vinchucas vivas... (AU)

A new tool for continuous detection of the presence of triatomine bugs, vectors of Chagas disease, in rural households

Ante la necesidad de contar con un dispositivo sencillo pero sensible para detectar triatominos domiciliarios y como parte del conjunto de actividades de vigilancia de la transmisión de la Enfermedad de Chagas en áreas rurales, mediante investigaciones realizadas en el INDIECH, se desarrolló un nuevo tipo de caja de cartulina denominado sensor María. La caja de cartulina rígida de 40x22x2cm, está abierta en ambos costados y en su extremo inferior, para permitir la libre entrada y salida de las vinchucas. En su interior contiene una cartulina blanda absorbente plegada en acordeón que posee una serie de orificios verticales a través de los cuales los insectos pueden desplazarse. El sensor María fue instalado dentro de los dormitorios de 38 viviendas en Amamá, Departamento de Moreno, y en 19 casas de Gramilla, Departamento de Gramilla, ambos de la provincia de Santiago del Estero. Estas localidadess no habían sido rociadas nunca con insecticidas, pero en Gramilla la densidad de vinchucas era inferior a la correspondiente a Amamá. En ambas localidades se comparó la sensibilidad de los sensores María para detectar la presencia de vinchucas en las casas, con la colecta manual de insectos por el método hora/hombre, correspondiente a un esfuerzo de 1 hora/hombre/casa utilizando movilizadores químicos. Dicha colecta manual se realizó al final de cada experimento que se prolongó por 30 días en Amamá y por 90 días en Gramilla. En Amamá los sensores María detectaron un 71% de casas infestadas mientras que por captura manual se registró un 79% de casas positivas. Los sensores detectaron el 90% de las viviendas de alta infestación por la presencia de evidencias (exuvias, huevos, rastros de materia fecal) y el 55% de ellas por la presencia de vinchucas vivas. En las casas de baja infestación, un 75% de los dormitorios tenían evidencias en los sensores y en un 30% de ellas se hallaron vinchucas vivas...