How the parts organize in the whole : a top-downview of molecular descriptors and properties for QSARand drug design

Sometimes the complexity of a system, or the properties derived from it, do depend neither on the individual characteristics of the components of the system nor on the nature of the physical forces that hold them together. In such cases the properties derived from the 'organization' of the system given by the connectivity of its elements can be determinant for explaining the structure of such systems. Here we explore the necessity of accounting for these structural characteristics in the molecular descriptors. We show that graph theory is the most appropriate mathematical theory to account for such molecular features. We review a method (TOPS-MODE) that is able to transform simple molecular descriptors, such as logP, polar surface area, molar refraction, charges, etc., into series of descriptors that account for the distribution of these characteristics (hydrophobicity, polarity, steric effects, etc) across the molecule. We explain the mathematical and physical principles of the TOPS-MODE method and develop three examples covering the description and interpretation of skin sensitisation of chemicals, chromosome aberration produced by organic molecules and drug binding to human serum albumin

The complex networks of earth minerals and chemical elements

We study the large-scale organization of the mineral-mineral (MMN) and element-element (EEN) complex networks by analyzing their topological structures. We see that the MMN and EEN are homogeneous, display large cliquishness, small average path length and large average degrees. Most of these networks display uniform degree distribution with the exception of the weighted EEN, which display a power-law degree distribution with exponential tail. All these topological characteristics appear to be consequence of the evolutionary mechanisms giving place to the minerals on Earth mantle, which as a whole display a relatively uniform major element composition. We also study the correlations between some topological network parameters and the abundance of chemical elements in different scenarios. Good correlation is obtained between the weighted degree and the abundance of elements in Earth's crustal rocks

Patogenia de la inflamación: discurso para los ejercicios del grado de Doctor de Santiago Ramón y Cajal

Tesis de doctorado leída en la Universidad Central el 26 de junio de 1877También disponible la reproducción digitalManuscrito firmadoTesis Doctorales históricasTesis Complutenses históricasmanuscritoFacultad de MedicinaFacultad de Medicinatruepu

Pío del Río-Hortega : A Visionary in the Pathology of Central Nervous System Tumors

Fondo de Investigaciones Sanitarias (11/00185), Redes Temáticasde Investigación Cooperativa en Salud (Ref. RD06/0020/1020).The last 140 years have seen considerable advances in knowledge of central nervous system tumors. However, the main tumor types had already been described during the early years of the twentieth century. The studies of Dr. Pío del Río Hortega have been ones of the most exhaustive histology and cytology-based studies of nervous system tumors. Río Hortega's work was performed using silver staining methods, which require a high level of practical skill and were therefore difficult to standardize. His technical aptitude and interest in nervous system tumors played a key role in the establishment of his classification, which was based on cell lineage and embryonic development. Río Hortega's approach was controversial when he proposed it. Current classifications are not only based on cell type and embryonic lineage, as well as on clinical characteristics, anatomical site, and age

Arrangement and terminations of nerves in the Œsophagus of mammalia

No Abstract.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50112/1/910100403_ftp.pd

Corrigendum : Pío del Río-Hortega: A Visionary in the Pathology of Central Nervous System Tumors

Fondo de Investigaciones Sanitarias (11/00185), Redes Temáticas de Investigación Cooperativa en Salud (Ref. RD06/0020/1020

Interplay Between ncRNAs and Cellular Communication: A Proposal for Understanding Cell-Specific Signaling Pathways

Intercellular communication is essential for the development of specialized cells, tissues, and organs and is critical in a variety of diseases including cancer. Current knowledge states that different cell types communicate by ligand–receptor interactions: hormones, growth factors, and cytokines are released into the extracellular space and act on receptors, which are often expressed in a cell-type-specific manner. Non-coding RNAs (ncRNAs) are emerging as newly identified communicating factors in both physiological and pathological states. This class of RNA encompasses microRNAs (miRNAs, well-studied post-transcriptional regulators of gene expression), long non-coding RNAs (lncRNAs) and other ncRNAs. lncRNAs are diverse in length, sequence, and structure (linear or circular), and their functions are described as transcriptional regulation, induction of epigenetic changes and even direct regulation of protein activity. They have also been reported to act as miRNA sponges, interacting with miRNA and modulating its availability to endogenous mRNA targets. Importantly, lncRNAs may have a cell-type-specific expression pattern. In this paper, we propose that lncRNA–miRNA interactions, analogous to receptor–ligand interactions, are responsible for cell-type-specific outcomes. Specific binding of miRNAs to lncRNAs may drive cell-type-specific signaling cascades and modulate biochemical feedback loops that ultimately determine cell identity and response to stress factors