Pretreatment of Urine Samples with SDS Improves Direct Identification of Urinary Tract Pathogens with Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry

We pretreated with SDS 71 urine samples with bacterial counts of >10⁵ CFU/ml and matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) identification scores of <2, in order to minimize failure rates. Identification improved in 46.5% of samples, remained unchanged in 49.3%, and worsened in 4.2%. The improvement was more evident for Gram-negative (54.3%) than for Gram-positive (32%) bacteria.     

Movimiento de alumnos ayudantes: experiencia de una institución cubana

The teaching-support student movement arose out of the necessity to cover the lack of teachers caused by the massive exodus of professionals at the beginning of the Cuban Revolution. Five decades later it is still alive and continuously perfects and adjusts itself according to the dynamic social requirements of the country. This article intends to describe the experience acquired at the University Hospital “Arnaldo Milián Castro” based on the work of teaching-support students in the period from 2011 to 2016, emphasising its achievements and challenges in the fulfilment of its main objectives in Cuban higher medical education such as: to support the development of the instructional and educational process, to address the professional orientation towards specialities deficient in professionals and to quickly acquire skills for teaching, research, and those related to specialities.     

A Novel 31.1 kb α-Thalassemia Deletion (– –MEX3) Found in a Mexican Family

α-Thalassemia (α-thal), a genetic disease characterized by microcytosis, hypochromia and anemia, is predominantly caused by deletions of the α-globin genes, HBA2 and HBA1. In this study, we describe a novel 31.1?kb α-thal deletion, – –^MEX3 (NC_000016.10: g.151479_182582del), observed in a Mexican family, probably originated from non homologous recombination between two Alu sequences; the 5′ Alu element has been involved in at least two other α-thal deletions [– –^FIL (NG_000006.1: g.11684_43534del) and – –^KOL] and possesses a core homologous sequence next to the – –^MEX3 breakpoint. In addition, a 286?bp insertion in an Alu sequence downstream to the – –^MEX3 3′ breakpoint was found in the studied family, – –^FIL carriers, and healthy subjects, suggesting a common genetic variation in the Mexican population. We highlight the involvement of Alu elements and their core sequence in the origin of deletions in the α-globin gene cluster, and the importance of characterizing rare mutations, to better understand DNA rearrangement origins.     

Mild hypothermia protects against oxygen glucose deprivation (OGD)-induced cell death in brain slices from adult mice

Most of neuroprotective strategies in stroke have failed to move from bench to bedside. One explanation might be the use of excessive uniform and smooth experimental models. Therefore, we have employed a more stringent in vitro model based on cultured brain slices from adult mice submitted to OGD. Using this acute model, we have confirmed that mild hypothermia protects against OGD-induced cell death when cooling the tissue during and after OGD, but not when hypothermia is induced only during reoxygenation.     

Extraction of artefactual MRS patterns from a large database using non-negative matrix factorization

Despite the success of automated pattern recognition methods in problems of human brain tumor diagnostic classification, limited attention has been paid to the issue of automated data quality assessment in the field of MRS for neuro-oncology. Beyond some early attempts to address this issue, the current standard in practice is MRS quality control through human (expert-based) assessment. One aspect of automatic quality control is the problem of detecting artefacts in MRS data. Artefacts, whose variety has already been reviewed in some detail and some of which may even escape human quality control, have a negative influence in pattern recognition methods attempting to assist tumor characterization. The automatic detection of MRS artefacts should be beneficial for radiology as it guarantees more reliable tumor characterizations, as well as the development of more robust pattern recognition-based tumor classifiers and more trustable MRS data processing and analysis pipelines. Feature extraction methods have previously been used to help distinguishing between good and bad quality spectra to apply subsequent supervised pattern recognition techniques. In this study, we apply feature extraction differently and use a variant of a method for blind source separation, namely Convex Non-Negative Matrix Factorization, to unveil MRS signal sources in a completely unsupervised way. We hypothesize that, while most sources will correspond to the different tumor patterns, some of them will reflect signal artefacts. The experimental work reported in this paper, analyzing a combined short and long echo time ¹H-MRS database of more than 2000 spectra acquired at 1.5T and corresponding to different tumor types and other anomalous masses, provides a first proof of concept that points to the possible validity of this approach.