The measurements of vehicle glow on the Space Shuttle

From the combined data set of glow observations on STS-3, STS-4 and STS-5 some of the properties of the shuttle glow were observed. Comparison of the STS-3 (240 km) and STS-5 (305 km) photographs show that the intensity of the glow is about a factor of 3.5 brighter on the low altitude (STS-3) flight. The orbiter was purposely rotated about the x axis in an experiment on STS-5 to observe the dependence of the intensity on the angle of incidence between the spacecraft surface normal and the velocity vector. For a relatively large angle between the velocity vector and the surface normal there is an appreciable glow, provided the surface is not shadowed by some other spacecraft structure. As the angle becomes less the glow intensifies. The grating experiments (STS-4 photography only, STS-5 image intensifier photography) provided a preliminary low resolution spectra of the spacecraft glow. Accurate wavelength calibrations of the STS-5 instrument permitted measuring of the spectrum and intensity of the Earth's airglow

ECVAM retrospective validation of in vitro micronucleus test (MNT)

In the past decade several studies comparing the in vitro chromosome aberration test (CAT) and the in vitro micronucleus test (MNT) were performed. A high correlation was observed in each of the studies (>85%); however, no formal validation for the micronucleus in vitro assay had been carried out. Therefore, a working group was established by the European Centre for the Validation of Alternative Methods (ECVAM) to perform a retrospective validation of the existing data, in order to evaluate the validity of the in vitro MNT on the basis of the modular validation approach. The primary focus of this retrospective validation was on the evaluation of the potential of the in vitro MNT as alternative to the standard in vitro CAT. The working group evaluated, in a first step, the available published data and came to the conclusion that two studies [German ring trial, von der Hude, W., Kalweit, S., Engelhardt, G. et al. (2000) In-vitro micronucleus assay with Chinese hamster V79 cells: results of a collaborative study with 26 chemicals. Mutat. Res., 468, 137–163, and SFTG International Collaborative Study, Lorge, E., Thybaud, V., Aardema, M., Oliver, J., Wataka, A., Lorenzon, G. and Marzin, D. (2006) SFTG International Collaborative Study on in-vitro micronucleus test I. General conditions and overall conclusions of the study. Mutat. Res., 607, 13–36] met the criteria for a retrospective validation according to the criteria previously defined by the working group. These two studies were evaluated in depth (including the reanalysis of raw data) and provided the information required for assessing the reliability (reproducibility) of the test. For the assessment of the concordance between the in vitro MNT and the in vitro CAT, additional published data were considered. Based on this retrospective validation, the ECVAM Validation Management Team concluded that the in vitro MNT is reliable and relevant and can therefore be used as an alternative method to the in vitro CAT. Following peer review, these conclusions were formally endorsed by the ECVAM Scientific Advisory Committee

Coma hipopotasémico: a propósito de un caso

Introduction: coma is the extreme degradation of consciousness. A syndrome characterized by a loss of vegetative functions, as an expression of acute and severe brain dysfunction.Presentation of the case: a 65-year-old male patient who two years ago commenced showing signs of loss of consciousness for two days In inter-crisis periods the studies did not confirm positive results. He was brought to the emergency room in a state of hyporeflexic coma. All parameters were normal except for a very discrete metabolic alkalosis and severe hypokalemia with 1,3 millimoles of potassium. General measures and complementary examinations were performed. Potassium values were replenished. As the potassium values standardized, a process of consciousness recovery was initiated. It was interpreted as a hypokalemic coma.Conclusions: hypopotassemia is a common imbalance, with repercussions in the different systems; this imbalance can result in alterations of the cardiovascular dynamics, progressive muscle weakness and coma. Therefore, in case of symptoms similar to hypokalemia, it is required to work on its diagnosis and treatment.Introducción: El coma es la máxima degradación del estado de conciencia. Síndrome caracterizado por una pérdida de las funciones de la vida de relación y conservación de las de la vida vegetativa, como expresión de una disfunción cerebral aguda y grave.Presentación del caso: paciente masculino de 65 años de edad que hace dos años comenzó con cuadros de pérdida de conciencia por espacio de dos días. En períodos intercrisis los estudios no arrojaron resultados positivos. Es traído a servicio de urgencia en estado de coma hiporrefléctico. Se tomaron medidas generales y se realizaron complementarios. Todo en parámetros de normalidad excepto por una muy discreta alcalosis metabólica y una hipocaliemia severa con 1,3 mili moles de potasio. Se reponen valores de potasio. En la medida que los valores de potasio se recuperaban se iniciaba un proceso de recuperación de la conciencia. Se interpreta como un coma hipopotasémico.Conclusiones: la hipopotasemia es un desbalance común, con repercusiones en los diferentes sistemas, que puede causar desde alteraciones de la dinámica cardiovascular, debilidad muscular progresiva y coma.  De ahí que ante sintomatologías similares a una hipopotasemia se deba trabajar en su diagnóstico y tratamiento.