Biomedical subjects

Fernando Moya

Publications and source records attributed to Fernando Moya.

6 recordsLinked to original sources

PubMed2006

Neurons in motion: same principles for different shapes?

The special conformation of the developing nervous system, in which progenitor zones are largely confined to the lumen of the neural tube, places neuronal migration as one of the most fundamental processes in brain development. Previous studies have shown that different neuronal types adopt distinct morphological modes of migration in the developing brain, indicating that neuronal migration might be a diverse process. Here, we review recent data on the molecular mechanisms underlying neuronal migration that suggest that similar signaling principles are responsible for the frequently variable morphology of different types of migrating neuron. According to this idea, the same basic molecular mechanisms found in other cell types, such as fibroblasts, might have been adapted to the special morphological needs of migrating neurons in different regions of the developing brain.

Animals↗

PubMed2006

A primary cell culture of Drosophila postembryonic larval neuroblasts to study cell cycle and asymmetric division.

Drosophila melanogaster is a key model system that has greatly contributed to the advance of developmental biology through its extensive and sophisticated genetics. Nevertheless, only a few in vitro approaches are available in Drosophila to complement genetic studies in order to better elucidate developmental mechanisms at the cellular and molecular level. Here we present a dissociated cell culture system generated from the optic lobes of Drosophila larval brain. This culture system makes it feasible to study the proliferative properties of Drosophila postembryonic Nbs by allowing BrdU pulse and chase assays, as well as detailed immunocytochemical analysis with molecular markers. These immunofluorescence experiments allowed us to conclude that localization of asymmetric cell division markers such as Inscuteable, Miranda, Prospero and Numb is cell autonomous. By time-lapse video recording we have observed interesting cellular features of postembryonic neurogenesis such us the polarized genesis of the neuroblast progeny, the extremely short ganglion mother cell (GMC) cell cycle, and the last division of a neuroblast lineage. The combination of this cell culture system and genetic tools of Drosophila will provide a powerful experimental model for the analysis of cell cycle and asymmetric cell division of neural progenitor cells.

Animals↗

PubMed2005

Population pharmacokinetics of cefepime in the neonate.

Newborn infants cared for in neonatal intensive care units may develop nosocomial infections. Cefepime, a "fourth-generation" cephalosporin (i.e., with activity against virtually all of the chromosomal-beta-lactamase-producing and many extended-spectrum-beta-lactamase-producing organisms), provides excellent activity against many gram-negative pathogens resistant to expanded-spectrum cephalosporins currently used to treat neonatal infections. The purpose of this study was to determine the pharmacokinetics of cefepime in this population to optimize dosing and minimize potential adverse events. Premature and term infants <4 months of age hospitalized in two neonatal intensive care units were studied. Limited pharmacokinetic (PK) sampling occurred following a dose of cefepime at 50 mg/kg of body weight infused over 30 min. Population pharmacokinetic parameters were determined using the program NONMEM. Fifty-five infants were enrolled. Their average (+/- standard deviation) gestational age at birth was 30.5 +/- 5.3 weeks, and their average postnatal age at PK evaluation was 14.5 +/- 14.7 days. In the final PK model, cefepime clearance (CL) was strongly associated with serum creatinine (SCr) (CL [ml/min/kg] = 0.26 + 0.59/SCr). The volume of distribution for infants with a postconceptional age of <30 weeks was larger than that for infants with a postconceptional age of >30 weeks (0.51 versus 0.39 liter/kg, respectively). The Bayesian analysis-predicted cefepime trough concentration at a dose of 50 mg/kg every 12 h for infants < or = 14 days of age was 29.9 +/- 16.6 microg/ml. Cefepime, dosed at 30 mg/kg/dose every 12 h for infants less than 14 days of age, regardless of gestational age, should provide antibiotic exposure equivalent to or greater than 50 mg/kg every 8 h in older infants and children.

Anti-Bacterial Agents↗

PubMed2004

Polarized increase of calcium and nucleokinesis in tangentially migrating neurons.

Cortical interneurons originate from the ganglionic eminences and reach their final position in the cortex via tangential migratory routes. The mechanisms of this migration are poorly understood. Here we have performed confocal time-lapse analysis of cell movement in the intermediate zone of embryonic mouse cortical slices in order to directly visualize their mode of migration. Tangentially migrating neurons moved by nucleokinesis, characterized by active phases of discontinuous advances of the nucleus followed by periods of quiescence. Dissociated cells from the ganglionic eminences also showed nucleokinesis associated with an increase of intracellular calcium, [Ca(2+)](i) Calcium elevation was greatest in the proximal region of the leading process, a zone with a wide distribution of gamma-tubulin. General increases in [Ca(2+)](i) elicited by microperfussion with neurotransmitters did not elicit nucleokinesis. These results show that tangential migration uses nucleokinesis, a cell-intrinsic process in which calcium signalling is local, directional and highly regulated.

Animals↗

PubMed2004

Early surfactant for neonates with mild to moderate respiratory distress syndrome: a multicenter, randomized trial.

OBJECTIVE: We studied the efficacy and safety of electively providing surfactant to preterm infants with mild to moderate respiratory distress syndrome (RDS) not requiring mechanical ventilation. STUDY DESIGN: A 5-center, randomized clinical trial was performed on 132 infants with RDS, birth weight >or=1250 grams, gestational age or=40% for >or=1 hour, and no immediate need for intubation. Infants were randomly assigned to intubation, surfactant (Survanta, Ross Laboratories, Columbus, Ohio) administration, and expedited extubation (n=65) or expectant management (n=67) with subsequent intubation and surfactant treatment as clinically indicated. The primary outcome was duration of mechanical ventilation. RESULTS: Infants in the surfactant group had a median duration of mechanical ventilation of 2.2 hours compared with 0.0 hours for control infants, since only 29 of 67 control infants required mechanical ventilation (P=.001). Surfactant-treated infants were less likely to require subsequent mechanical ventilation for worsening respiratory disease (26% vs 43%, relative risk=0.60; 95% CI, 0.37, 0.99). There were no differences in secondary outcomes (duration of nasal continuous positive airway pressure, oxygen therapy, hospital stay, or adverse outcomes). CONCLUSIONS: Routine elective intubation for administration of surfactant to preterm infants >or=1250 grams with mild to moderate RDS is not recommended.

Female↗

PubMed2002

A randomized, controlled, double-blind trial comparing two loading doses of aminophylline.

OBJECTIVE: To compare 8 mg/kg and 6 mg/kg loading doses of aminophylline. STUDY DESIGN: Sixty-one preterm infants weighing <1500 g were enrolled once a decision to administer intravenous aminophylline was made. A standard maintenance dose was used. Serum levels of theophylline were drawn 8 hours after the loading dose and before the fifth maintenance dose. RESULTS: After the initial loading dose, the 8 mg/kg group achieved recommended serum theophylline levels (7-12 microg/ml) more frequently than the 6 mg/kg group (39% vs 3%, p=0.002). Subsequent levels were similar between the groups. There were no increases in side effects with the higher loading dose. CONCLUSION: If a clinical decision to start intravenous aminophylline therapy in preterm infants has been made, the use of an 8 mg/kg loading dose appears to be a better and safe way to quickly achieve serum theophylline levels within the recommended range.

Aminophylline↗