Drug interactions may be important risk factors for methotrexate neurotoxicity, particularly in pediatric leukemia patients

Purpose: Methotrexate administration is associated with frequent adverse neurological events during treatment for childhood acute lymphoblastic leukemia. Here, we present evidence to support the role of common drug interactions and low vitamin B12 levels in potentiating methotrexate neurotoxicity. Methods: We review the published evidence and highlight key potential drug interactions as well as present clinical evidence of severe methotrexate neurotoxicity in conjunction with nitrous oxide anesthesia and measurements of vitamin B12 levels among pediatric leukemia patients during therapy. Results: We describe a very plausible mechanism for methotrexate neurotoxicity in pediatric leukemia patients involving reduction in methionine and consequential disruption of myelin production. We provide evidence that a number of commonly prescribed drugs in pediatric leukemia management interact with the same folate biosynthetic pathways and/or reduce functional vitamin B12 levels and hence are likely to increase the toxicity of methotrexate in these patients. We also present a brief case study supporting out hypothesis that nitrous oxide contributes to methotrexate neurotoxicity and a nutritional study, showing that patients. Conclusions: Use of nitrous oxide in pediatric leukemia patients at the same time as methotrexate use should be avoided especially as many suitable alternative anesthetic agents exist. Clinicians should consider monitoring levels of vitamin B12 in patients suspected of having methotrexate- induced neurotoxic effects

Reply: Methotrexate neurotoxicity due to drug interactions: an inadequate folinic acid effect

No abstract available

Note: Autonomous Pulsed Power Generator Based on Transverse Shock Wave Depolarization of Ferroelectric Ceramics

Autonomous pulsed generators utilizing transverse shock wave depolarization (shock front propagates across the polarization vector P0) of Pb(Zr0.52Ti0.48)O3 poled piezoelectric ceramics were designed, constructed, and experimentally tested. It was demonstrated that generators having total volume of 50 cm3 were capable of producing the output voltage pulses with amplitude up to 43 kV with pulse duration 4 µs. A comparison of high-voltage operation of transverse and longitudinal shock wave ferroelectric generators is given

Coupled Particle Transport and Pattern Formation in a Nonlinear Leaky-Box Model

Effects of particle-particle coupling on particle characteristics in nonlinear leaky-box type descriptions of the acceleration and transport of energetic particles in space plasmas are examined in the framework of a simple two-particle model based on the Fokker-Planck equation in momentum space. In this model, the two particles are assumed coupled via a common nonlinear source term. In analogy with a prototypical mathematical system of diffusion-driven instability, this work demonstrates that steady-state patterns with strong dependence on the magnetic turbulence but a rather weak one on the coupled particles attributes can emerge in solutions of a nonlinearly coupled leaky-box model. The insight gained from this simple model may be of wider use and significance to nonlinearly coupled leaky-box type descriptions in general

Rotons and Quantum Evaporation from Superfluid 4He

The probability of evaporation induced by $R^+$ and $R^-$ rotons at the surface of superfluid helium is calculated using time dependent density functional theory. We consider excitation energies and incident angles such that phonons do not take part in the scattering process. We predict sizable evaporation rates, which originate entirely from quantum effects. Results for the atomic reflectivity and for the probability of the roton change-mode reflection are also presented.Comment: 11 pages, REVTEX, 3 figures available upon request or at http://anubis.science.unitn.it/~dalfovo/papers/papers.htm

De Litteris

This book is drawn from a series of annual faculty lectures at Connecticut College. The contents are Some Philosophical Remarks About Poetry, Robert W. Jordan Linguistics and Rhetoric, Eugene P. Cognon Literary Problems in Interpreting Paul\u27s Letters, Gordon P. Wiles Iris Sacred and Profane: the Philosopher as Novelist, Susan M. Woody Toward an American Epic: Four Poets, James R. Baird 1100 A.D.: A Crisis for Us?, F. Edward Cranz Of Messages and Messengers, Marijan Despalotovichttps://digitalcommons.conncoll.edu/ccbooks/1006/thumbnail.jp

Pd/Cr Gates for a MIS Type Hydrogen Sensor

Instead of the pure Pd gates in MIS type hydrogen sensor, Pd-Cr alloy gates with different composition and structure were used to improve the sensors performance. The use of Pd-Cr alloy not only extended the dynamic range from 100 ppm to 50,000 ppm of hydrogen, but also showed quick response. The dynamic range and sensitivity were related to the nature of metal outer surface and the metal/insulator interface respectively