The role of dwelling type when estimating the effect of magnetic fields on childhood leukemia in the California Power Line Study (CAPS).

PurposeThe type of dwelling where a child lives is an important factor when considering residential exposure to environmental agents. In this paper, we explore its role when estimating the potential effects of magnetic fields (MF) on leukemia using data from the California Power Line Study (CAPS). In this context, dwelling type could be a risk factor, a proxy for other risk factors, a cause of MF exposure, a confounder, an effect-measure modifier, or some combination.MethodsWe obtained information on type of dwelling at birth on over 2,000 subjects. Using multivariable-adjusted logistic regression, we assessed whether dwelling type was a risk factor for childhood leukemia, which covariates and MF exposures were associated with dwelling type, and whether dwelling type was a potential confounder or an effect-measure modifier in the MF-leukemia relationship under the assumption of no-uncontrolled confounding.ResultsA majority of children lived in single-family homes or duplexes (70%). Dwelling type was associated with race/ethnicity and socioeconomic status but not with childhood leukemia risk, after other adjustments, and did not alter the MF-leukemia relationship upon adjustment as a potential confounder. Stratification revealed potential effect-measure modification by dwelling type on the multiplicative scale.ConclusionDwelling type does not appear to play a significant role in the MF-leukemia relationship in the CAPS dataset as a leukemia risk factor or confounder. Future research should explore the role of dwelling as an effect-measure modifier of the MF-leukemia association

Validation of a self-reported work disability questionnaire for ulcerative colitis

Ulcerative colitis (UC) may severely limit patients'' capacity to work. Recently, we validated a work disability questionnaire (WDQ) for Crohn disease. As UC shares clinical characteristics with Crohn disease, we hypothesized that the questionnaire might also be useful for UC. The study was aimed to validate the WDQ for use in UC. Consecutive patients with UC (n = 142, 67 women; age 48 +/- 1) completed the UC-WDQ and the inflammatory bowel disease questionnaire-9 (IBDQ-9), and EuroQoL-5D quality-of-life questionnaires. Validation of the UC-WDQ included an assessment of its construct validity, including: discriminant validity, convergent validity, and reproducibility (test-retest). We also calculated the intraclass correlation and the Cronbach alpha. 1. Discriminant validity: Mean UC-WDQ scores were 12.8 +/- 4.4 (remission phase) and 17.2 +/- 6.1 (with clinical activity) (P < .05). 2. Convergent validity: The correlations of UC-WDQ were r = 0.74 (P < .001) with IBDQ, r = 0.44 (P < .01) with disease activity, r = 0.56 (P < .01) with EuroQoL-5D, and r = 0.60 (P < .01) with the EuroQoL-5D visual scale. 3. Reproducibility: Test-retest reproducibility: UC-WDQ scores obtained after a 2-week interval were similar (15.8 vs 15.1), (r = 0.91, P < .01). Intraclass correlation was 0.93 (95% confidence interval 0.92-0.95). Cronbach alpha was 0.94. The UC-WDQ is a valid and reliable tool for measuring work disability in patients with UC

The future of direct cardiac reprogramming: any GMT cocktail variety?

Direct cardiac reprogramming has emerged as a novel therapeutic approach to treat and regenerate injured hearts through the direct conversion of fibroblasts into cardiac cells. Most studies have focused on the reprogramming of fibroblasts into induced cardiomyocytes (iCMs). The first study in which this technology was described, showed that at least a combination of three transcription factors, GATA4, MEF2C and TBX5 (GMT cocktail), was required for the reprogramming into iCMs in vitro using mouse cells. However, this was later demonstrated to be insufficient for the reprogramming of human cells and additional factors were required. Thereafter, most studies have focused on implementing reprogramming efficiency and obtaining fully reprogrammed and functional iCMs, by the incorporation of other transcription factors, microRNAs or small molecules to the original GMT cocktail. In this respect, great advances have been made in recent years. However, there is still no consensus on which of these GMT-based varieties is best, and robust and highly reproducible protocols are still urgently required, especially in the case of human cells. On the other hand, apart from CMs, other cells such as endothelial and smooth muscle cells to form new blood vessels will be fundamental for the correct reconstruction of damaged cardiac tissue. With this aim, several studies have centered on the direct reprogramming of fibroblasts into induced cardiac progenitor cells (iCPCs) able to give rise to all myocardial cell lineages. Especially interesting are reports in which multipotent and highly expandable mouse iCPCs have been obtained, suggesting that clinically relevant amounts of these cells could be created. However, as of yet, this has not been achieved with human iCPCs, and exactly what stage of maturity is appropriate for a cell therapy product remains an open question. Nonetheless, the major concern in regenerative medicine is the poor retention, survival, and engraftment of transplanted cells in the cardiac tissue. To circumvent this issue, several cell pre-conditioning approaches are currently being explored. As an alternative to cell injection, in vivo reprogramming may face fewer barriers for its translation to the clinic. This approach has achieved better results in terms of efficiency and iCMs maturity in mouse models, indicating that the heart environment can favor this process. In this context, in recent years some studies have focused on the development of safer delivery systems such as Sendai virus, Adenovirus, chemical cocktails or nanoparticles. This article provides an in-depth review of the in vitro and in vivo cardiac reprograming technology used in mouse and human cells to obtain iCMs and iCPCs, and discusses what challenges still lie ahead and what hurdles are to be overcome before results from this field can be transferred to the clinical settings

On the short-term relationship between solar soft X-ray irradiances and equatorial total electron content (TEC)

[1] The relationship between total electron content (TEC) and the solar soft X-ray irradiances is presented. Three bands ( 2 - 7 nm, 6 - 19 nm, and 17 - 20 nm) of solar soft X-ray measurements from the Student Nitric Oxide Explorer (SNOE) satellite are examined and all show a similar relationship with TEC. The TEC data are from a GPS receiver near Ancon, Peru ( - 11.78 degrees latitude, - 77.15 degrees longitude) from 11 March 1998 to 23 August 1999 and 2 October 1999 to 10 June 2000. During these periods the average TEC measurement was calculated from all observations whose ionospheric pierce point occurred within - 12 +/- 2 degrees latitude and - 77 +/- 2 degrees longitude and within the hour selected. TEC shows a more significant correlation with soft X-ray irradiances than with F10.7. The X rays lead the TEC by approximately 0.8 - 1.3 days, which is consistent with the neutral density affecting the TEC. The magnitude of these short term ( 27 days or less) changes is approximately 0.18 of the total TEC. During the period examined geomagnetic activity, as represented by Ap, could account for half as much variation in TEC (0.1 of the total TEC) as the solar irradiance

Residential mobility and childhood leukemia.

AimsStudies of environmental exposures and childhood leukemia studies do not usually account for residential mobility. Yet, in addition to being a potential risk factor, mobility can induce selection bias, confounding, or measurement error in such studies. Using data collected for California Powerline Study (CAPS), we attempt to disentangle the effect of mobility.MethodsWe analyzed data from a population-based case-control study of childhood leukemia using cases who were born in California and diagnosed between 1988 and 2008 and birth certificate controls. We used stratified logistic regression, case-only analysis, and propensity-score adjustments to assess predictors of residential mobility between birth and diagnosis, and account for potential confounding due to residential mobility.ResultsChildren who moved tended to be older, lived in housing other than single-family homes, had younger mothers and fewer siblings, and were of lower socioeconomic status. Odds ratios for leukemia among non-movers living &lt;50 meters (m) from a 200+ kilovolt line (OR: 1.62; 95% CI: 0.72-3.65) and for calculated fields ≥ 0.4 microTesla (OR: 1.71; 95% CI: 0.65-4.52) were slightly higher than previously reported overall results. Adjustments for propensity scores based on all variables predictive of mobility, including dwelling type, increased odds ratios for leukemia to 2.61 (95% CI: 1.76-3.86) for living &lt; 50 m from a 200 + kilovolt line and to 1.98 (1.11-3.52) for calculated fields. Individual or propensity-score adjustments for all variables, except dwelling type, did not materially change the estimates of power line exposures on childhood leukemia.ConclusionThe residential mobility of childhood leukemia cases varied by several sociodemographic characteristics, but not by the distance to the nearest power line or calculated magnetic fields. Mobility appears to be an unlikely explanation for the associations observed between power lines exposure and childhood leukemia

El trasplante de células de la glía envolvente del bulbo olfatorio tras lesión de la médula espinal: Estudio experimental en ratas.

Objetivo Evaluar el efecto a largo plazo del trasplante de células de la glía envolvente (GE) del bulbo olfatorio tras lesión de la médula espinal. Material y método Se practicó una laminectomía dorsal T8, en 16 ratas adultas Sprague-Dawley, dejando al descubierto la médula espinal subyacente, la cual se bañó con rosa de Bengala durante 10 minutos, antes de lesionarla por iluminación con una fibra óptica acoplada a una lámpara halógena, durante 2,5 minutos. A la mitad de los animales se les inyectó 180.000 células de GE, en 10 μl de medio (grupo GE), y a la otra mitad sólo 10 μl de DMEM (Dulbecco's modified Eagle's medium) (grupo DM). Los animales se sacrificaron a los 90 días de efectuar la lesión y se evaluó el área de médula espinal preservada, la recuperación locomotora y la sensibilidad nociceptiva. Resultados Los animales del grupo GE mostraron un nivel de locomoción superior y retiraron antes la pata al estímulo nociceptivo que los del grupo DM. También hubo una mayor preservación de parénquima medular y más células p75 positivas en el grupo GE que en el DM. Conclusiones El trasplante de GE favorece la preservación de parénquima medular y evita la pérdida de funciones motoras y sensoriales en la rata

Fracaso del cartílago costal en el tratamiento de defectos óseos experimentales: Estudio histológico y radiológico

Se realiza un estudio experimental para demostrar la utilidad del cartílago costal, fresco o criopreservado (autólogo y homólogo), en el tratamiento de defectos óseos cavitarios de huesos largos y observar si la radiología simple es fiable para la valoración de su incorporación. Para ello se implanta cartílago costal, sin pericondrio, en un defecto óseo cavitario de la metáfisis distal del fémur de conejo. Se utilizan dos tipos de injerto según su procedencia (antólogo y homólogo) y el procedimiento de conservación (fresco y criopreservado). Se trabaja sobre 3 grupos de 6 conejos cada uno. Se valora la incorporación del injerto mediante histología y radiología simple, a las 3, 6 y 12 semanas. Las conclusiones de este trabajo demuestran que el implante de cartílago costal no actúa como elemento osteoinductor; la radiología simple no es un método fiable para la valoración de la incorporación del injerto.An experimental study was carried out to demonstrate the utility of costal, fresh or cryopreserved cartilage (autologus and homologous), in the treatment of cavitary bone defects of long bones and to observe whether simple radiology is reliable for assessing of its incorporation. The study involved implanting costal cartilage, without perichondrial tissue, in a cavitary bone defect of the distal metafisis in rabbit femur. Two types of graft were used, according to their origin (autologus and homologous) and to the conservation procedure (fresh and cryopreserved). We workek on 3 separate groups of 6 rabbits. We assessed the incorporation of the graft by means of histology and simple radiology studies, at 3, 6 and 12 weeks. The conclusions of this work demonstrate that costal cartilage implants do not act as osteoinductor elements, and that simple radiology is not a reliable method for assessing the incorporation of the graft

Feature selection for chemical sensor arrays using mutual information

We address the problem of feature selection for classifying a diverse set of chemicals using an array of metal oxide sensors. Our aim is to evaluate a filter approach to feature selection with reference to previous work, which used a wrapper approach on the same data set, and established best features and upper bounds on classification performance. We selected feature sets that exhibit the maximal mutual information with the identity of the chemicals. The selected features closely match those found to perform well in the previous study using a wrapper approach to conduct an exhaustive search of all permitted feature combinations. By comparing the classification performance of support vector machines (using features selected by mutual information) with the performance observed in the previous study, we found that while our approach does not always give the maximum possible classification performance, it always selects features that achieve classification performance approaching the optimum obtained by exhaustive search. We performed further classification using the selected feature set with some common classifiers and found that, for the selected features, Bayesian Networks gave the best performance. Finally, we compared the observed classification performances with the performance of classifiers using randomly selected features. We found that the selected features consistently outperformed randomly selected features for all tested classifiers. The mutual information filter approach is therefore a computationally efficient method for selecting near optimal features for chemical sensor arrays

Generation of two transgene-free human iPSC lines from CD133+ cord blood cells

We have generated two human induced pluripotent stem cell (iPSC) lines from CD133+ cells isolated from umbilical cord blood (CB) of a female child using non-integrative Sendai virus. Here we describe the complete characterization of these iPSC lines: PRYDi-CB5 and PRYDi-CB40