Fragments Derived from Non-coding RNAs: How Complex is Genome Regulation?

The human genome is highly dynamic and only a small fraction of it codes for proteins, but most of the genome is transcribed, highlighting the importance of non-coding RNAs on cellular functions. In addition, it is now known the generation of non-coding RNAs fragments under particular cellular conditions and their functions have been revealed unexpected mechanisms of action, converging, in some cases, with the biogenic pathways and action machineries of microRNAs or Piwi-interacting RNAs. This led us to ask why the cell produces so many apparently redundant molecules to exert similar functions and regulate apparently convergent processes? However, non-coding RNAs fragments can also function similarly to aptamers, with secondary and tertiary conformations determining their functions. In the present work, it was reviewed and analyzed the current information about the non-coding RNAs fragments, describing their structure and the biogenic pathways producing them, with special emphasis on their cellular functions.

Growth of Very Low Birth Weight Infants Who Received a Liquid Human Milk Fortifier: A Randomized, Controlled Multicenter Trial.

OBJECTIVES: To evaluate growth (weight, length, head circumference, and knee-heel length [KHL]) in very low birth weight (VLBW) infants (500-1500 g) who received human milk with a liquid fortifier (LHMF) with high protein and fatty acid content versus a traditional powder fortifier (PHMF) for 45 days or until discharge. METHODS: This was a multicenter, randomized, controlled trial. An intention-to-treat analysis was performed to determine adverse events and withdrawal causes. We also performed an efficacy analysis involving the infants who completed at least 2 weeks of study. RESULTS: Of the 158 infants enrolled in the study, 146 completed at least 2 weeks, and 125 completed the entire study. The biodemographic characteristics were similar between groups, with no differences in increments of weight (22.9 vs 22.7 g kg-1 day-1), length (1.03 vs 1.09 cm/week), head circumference (0.91 vs 0.90 cm/week), or KHL (3.6 vs 3.3 mm/week). The KHL increment was greater in infants weighing >1 kg receiving LHMF (3.7 vs 3.2 mm/week, P = 0.027). Although there were no significant differences in serious adverse events, the incidence difference of the composite outcome death/necrotizing enterocolitis between groups warrants attention (1.3% with LHMF and 8.1% with PHMF). CONCLUSION: There were no differences in the overall growth between VLBW infants receiving either fortifier.

[Chromosomal imbalances and survival in patients with astrocytomas]. / Alteraciones cromosómicas y supervivencia en pacientes con astrocitomas.

BACKGROUND: Cytogenetics has revealed that the development of brain tumors might be induced by molecular alterations. The association of chromosomal imbalances with survival will allow for the prognosis and treatment of these tumors to be assessed. The objective of this study was to determine chromosomal imbalances and overall and disease-free survival in pediatric patients with astrocytoma and the association between chromosomal imbalances and survival. METHODS: Medical charts of patients diagnosed with astrocytoma according to records from 1995 to 2005 were reviewed. Paraffin blocks were retrieved in order to extract tumor material and a comparative genomic hybridization technique was used to search for chromosomal gains and losses. RESULTS: Out of 35 patients, 31 had at least some alteration in chromosomes 1, 5, 9 or 18, the latter with gains or losses in 65.7 % of the patients. By histology, 7/9 pilocytic astrocytomas had alteration of chromosome 9, and in 5/6 anaplastic astrocytomas, of chromosome 18. Patients with alterations in these chromosomes had a worse survival. CONCLUSIONS: The results of this study suggest that there is an association between the anaplastic histology and chromosome 18 alterations, as well as between diffuse astrocytoma and alterations in chromosome 5, which could be relevant in the Latin American population.

INTRODUCCIÓN: la citogenética ha revelado que el desarrollo de los tumores cerebrales pudiera estar inducido por alteraciones moleculares. La asociación de las alteraciones cromosómicas con la supervivencia permitirá valorar el pronóstico y tratamiento de estos tumores. El objetivo de este estudio fue determinar las alteraciones cromosómicas, la supervivencia global y libre de enfermedad en pacientes pediátricos con astrocitomas, y la asociación entre ellas. MÉTODOS: se revisaron los expedientes clínicos de los pacientes con diagnóstico de astrocitoma de acuerdo con los registros de 1995 a 2005. Se buscaron los bloques de parafina para extraer el material tumoral y se realizó técnica de hibridación genómica comparativa para buscar ganancias y pérdidas cromosómicas. RESULTADOS: de 35 pacientes, 31 presentaron al menos alguna alteración en los cromosomas 1, 5, 9 o 18, este último presentó ganancias o pérdidas en 65.7 % de los pacientes. Al analizarlas según la estirpe histológicas de los tumores, en 7/9 astrocitomas pilocíticos se observó alteración del cromosoma 9, y en 5/6 astrocitomas anaplásicos, del cromosoma 18. Los pacientes con alteraciones en estos cromosomas tuvieron una menor supervivencia. CONCLUSIONES: los resultados de este estudio sugieren que existe asociación entre la histología anaplásica y las alteraciones del cromosoma 18, así como entre el astrocitoma difuso y las alteraciones en el cromosoma 5, lo cual podría ser relevante en la población latinoamericana.