A predictive score for retinopathy of prematurity in very low birth weight preterm infants

Aims This study describes the development of a score based on cumulative risk factors for the prediction of severe retinopathy of prematurity (ROP) comparing the performance of the score against the birth weight (BW) and gestational age (GA) in order to predict the onset of ROP.Methods A prospective cohort of preterm infants with BWp1500 g and/or GAp32 weeks was studied. the score was developed based on BW, GA, proportional weight gain from birth to the 6th week of life, use of oxygen in mechanical ventilation, and need for blood transfusions from birth to the 6th week of life. the score was established after linear regression, considering the impact of each variable on the occurrences of any stage and severe ROP. Receiver operating characteristic (ROC) curves were used to determine the best sensitivity and specificity values for the score. All variables were entered into an Excel spreadsheet (Microsoft) for practical use by ophthalmologists during screening sessions.Results the sample included 474 patients. the area under the ROC curve for the score was 0.77 and 0.88 to predict any stage and severe ROP, respectively. These values were significantly higher for the score than for BW (0.71) and GA (0.69) when measured separately.Conclusions ROPScore is an excellent index of neonatal risk factors for ROP, which is easy to record and more accurate than BW and GA to predict any stage ROP or severe ROP in preterm infants. the scoring system is simple enough to be routinely used by ophthalmologists during screening examination for detection of ROP. Eye (2012) 26, 400-406; doi: 10.1038/eye. 2011.334; published online 23 December 2011Hosp Clin Porto Alegre, Dept Ophthalmol, BR-90035903 Porto Alegre, RS, BrazilUniv Fed Rio Grande do Sul, Dept Ophthalmol, Sch Med, Porto Alegre, RS, BrazilUniversidade Federal de São Paulo, Dept Ophthalmol, Sch Med, São Paulo, BrazilUniv Fed Rio Grande do Sul, Dept Paediat, Newborn Sect, Sch Med, Porto Alegre, RS, BrazilUniversidade Federal de São Paulo, Dept Ophthalmol, Sch Med, São Paulo, BrazilWeb of Scienc

Models predicting the growth response to growth hormone treatment in short children independent of GH status, birth size and gestational age

<p>Abstract</p> <p>Background</p> <p>Mathematical models can be used to predict individual growth responses to growth hormone (GH) therapy. The aim of this study was to construct and validate high-precision models to predict the growth response to GH treatment of short children, independent of their GH status, birth size and gestational age. As the GH doses are included, these models can be used to individualize treatment.</p> <p>Methods</p> <p>Growth data from 415 short prepubertal children were used to construct models for predicting the growth response during the first years of GH therapy. The performance of the models was validated with data from a separate cohort of 112 children using the same inclusion criteria.</p> <p>Results</p> <p>Using only auxological data, the model had a standard error of the residuals (SD_res), of 0.23 SDS. The model was improved when endocrine data (GH_maxprofile, IGF-I and leptin) collected before starting GH treatment were included. Inclusion of these data resulted in a decrease of the SD_resto 0.15 SDS (corresponding to 1.1 cm in a 3-year-old child and 1.6 cm in a 7-year old). Validation of these models with a separate cohort, showed similar SD_resfor both types of models. Preterm children were not included in the Model group, but predictions for this group were within the expected range.</p> <p>Conclusion</p> <p>These prediction models can with high accuracy be used to identify short children who will benefit from GH treatment. They are clinically useful as they are constructed using data from short children with a broad range of GH secretory status, birth size and gestational age.</p

Relationship between Exercise Capacity and Brain Size in Mammals

A great deal of experimental research supports strong associations between exercise, cognition, neurogenesis and neuroprotection in mammals. Much of this work has focused on neurogenesis in individual subjects in a limited number of species. However, no study to date has examined the relationship between exercise and neurobiology across a wide range of mammalian taxa. It is possible that exercise and neurobiology are related across evolutionary time. To test this hypothesis, this study examines the association between exercise and brain size across a wide range of mammals.Controlling for associations with body size, we examined the correlation between brain size and a proxy for exercise frequency and capacity, maximum metabolic rate (MMR; ml O(2) min(-1)). We collected brain sizes and MMRs from the literature and calculated residuals from the least-squares regression line describing the relationship between body mass and each variable of interest. We then analyzed the correlation between residual brain size and residual MMR both before and after controlling for phylogeny using phylogenetic independent contrasts. We found a significant positive correlation between maximum metabolic rate and brain size across a wide range of taxa.These results suggest a novel hypothesis that links brain size to the evolution of locomotor behaviors in a wide variety of mammalian species. In the end, we suggest that some portion of brain size in nonhuman mammals may have evolved in conjunction with increases in exercise capacity rather than solely in response to selection related to cognitive abilities

Pheromone dialects in European turnip moths Agrotis segetum

Female pheromone gland extracts from cultures of Agrotis segetum (Schiff.), originating from Sweden, France, Hungary and England were analysed for pheromone components and precursors (fatty acids). The pheromone blends were similar in the moths from the Swedish, English and Hungarian populations, whereas the French diverged with a much higher amount of (Z)-5-decenyl acetate relative to the homologous pheromone components (Z)-7-dodecenyl acetate and (Z)-9-tetradecenyl acetate. The frequency of receptor cells sensitive to (Z)-5-decenyl acetate on male antennae, was also highest in the French insects. In correspondence with the earlier reported behavioural significance of (Z)-5-decenyl acetate in the French turnip moth, this is indicative of a French pheromone dialect. The biosynthetic basis for the shift in pheromone production as well as ecological and evolutionary implications of the findings are discussed

New insights into the development of retinopathy of prematurity - importance of early weight gain

Evidence is accumulating that one of the strongest predictors of retinopathy of prematurity (ROP), in addition to low gestational age, is poor weight gain during the first weeks of life. In infants born preterm, the retina is not fully vascularised. The more premature the child, the larger is the avascular area. In response to hypoxia, vascular endothelial growth factor (VEGF) is secreted. For appropriate VEGF-induced vessel growth, sufficient levels of insulin-like growth factor I (IGF-I) in serum are necessary. IGF-I is a peptide, related to nutrition supply, which is essential for both pre- and post-natal general growth as well as for growth of the retinal vasculature. In prematurely born infants, serum levels are closely related to gestational age and are lower in more prematurely born infants. At preterm birth the placental supply of nutrients is lost, growth factors are suddenly reduced and general as well as vascular growth slows down or ceases. In addition, the relative hyperoxia of the extra-uterine milieu, together with supplemental oxygen, causes a regression of already developed retinal vessels. Postnatal growth retardation is a major problem in very preterm infants. Both poor early weight gain and low serum levels of IGF-I during the first weeks/months of life have been found to be correlated with severity of ROP. Conclusion: This review will focus on the mechanisms leading to ROP by exploring factors responsible for poor early weight gain and abnormal vascularisation of the eye of the preterm infant

Rimbaud, entre le Parnasse et la prose - parcours du signifiant

En choisissant comme sujet de mémoire de maîtrise la poésie d'Arthur Rimbaud, je n'ignorais pas que ses écrits avaient été commentés et analysés à peu près de toutes les façons. Il me fallait donc trouver une approche "neuve", c'est-à-dire qui s'écarte de la biographie et de tout ce qui gravite autour du "mythe" Rimbaud, une approche qui soit concentrée à l'intérieur d'une période cruciale de sa courte aventure littéraire. Au moyen de l'analyse textuelle, j'ai d'abord jeté un regard critique au plan de la forme particulière que revêt cette écriture et, conjointement, au plan de l'expression que cette même forme devait exposer pendant la dite période temporelle. L'idée qui a servi de point de départ à cette démarche analytique est la suivante: Rimbaud n'a jamais cessé de faire des expériences, des jeux sur le signifiant, tout en gardant toujours présents et vivaces les mêmes thèmes qui ont motivé ses premiers poèmes, du temps où il souhaitait être accueilli par ses aînés au sein du Parnasse. "Entre le Parnasse et la prose ?" est la formule qui traduit ce hiatus, cet intervalle inscrit dans le temps (1871-1873), tandis que "parcours du signifiant" cherche à établir la relation que l'on peut faire au plan sémantique entre les différents thèmes qui servirent de canevas à l'évolution de son style. Ainsi, au plan du contenu, le poème "Soleil et Chair" traduit les préoccupations mythico-idéologiques et socialisantes des créateurs de l'art pour l'art, auxquels Rimbaud s'est identifié clairement, tandis qu'au plan de l'expression, "Voyelles" établit une base, un appareil circulaire mettant en scène des voyelles, un outil avec lequel il se permettra de remettre en scène les idées sur lesquelles il appuie sa théorie de "voyance". J'ai cru bon de consacrer tout le premier chapitre à la mise en relief des différentes théories actuelles qui ont la faveur du milieu des études littéraires au plan du signifiant linguistique, de façon à faire comprendre sur quelle structure d'appui s'élaborait ma recherche. Certaines stratégies employées pour en arriver à mon double but pourront surprendre l'éventuel lecteur de ce mémoire, mais elles trouveront leur justification d'elles-mêmes au fur et à mesure que l'analyse des textes rimbaldiens se poursuivra selon la logique particulière qui leur est propre. Par exemple, j'ai décidé de citer un poème-témoignage de Paul Verlaine intitulé "Crimen Amoris" afin d'étayer la thèse de la recherche de la "voyance" et du "raisonné dérèglement de tous les sens" annoncés dans "La lettre du Voyant". Ce texte de Verlaine, écrit pendant son emprisonnement en Belgique en 1873, n'a pas servi d'appui pour analyser l'écriture rimbaldienne, mais il sert à confirmer qu'il y eut pour Rimbaud une période pendant laquelle il s'adonna à des expériences dans le but de "changer la vie", de transmuter aussi bien l'écriture que la nature humaine. Mon analyse couvre donc la période que termine l'écriture par Rimbaud d'Une saison en enfer et qui, selon mes propres conclusions, précède celle des Illuminations. Je considère qu'Une saison en enfer (et surtout "Alchimie du verbe") constitue le compte rendu de l'expérience de voyance annoncée dans la "Lettre du voyant", une prise de conscience que Rimbaud aura voulu matérialiser avant de passer à autre chose, à un travail davantage axé sur la forme que sur le contenu, quoique les mêmes vieilles et récurrentes obsessions soient toujours prêtes à remonter à la surface dans Illuminations, mais je le précise, cette phase terminale de son oeuvre ne fait pas l'objet du présent mémoire puisqu'elle relève d'une démarche tout à fait différente de celle qui concerne le contenu de ce mémoire

Role of Insulinlike Growth Factor 1 in Fetal Development and in the Early Postnatal Life of Premature Infants

The neonatal period of very preterm infants is often characterized by a difficult adjustment to extrauterine life, with an inadequate nutrient supply and insufficient levels of growth factors, resulting in poor growth and a high morbidity rate. Long-term multisystem complications include cognitive, behavioral, and motor dysfunction as a result of brain damage as well as visual and hearing deficits and metabolic disorders that persist into adulthood. Insulinlike growth factor 1 (IGF-1) is a major regulator of fetal growth and development of most organs especially the central nervous system including the retina. Glucose metabolism in the developing brain is controlled by IGF-1 which also stimulates differentiation and prevents apoptosis. Serum concentrations of IGF-1 decrease to very low levels after very preterm birth and remain low for most of the perinatal development. Strong correlations have been found between low neonatal serum concentrations of IGF-1 and poor brain and retinal growth as well as poor general growth with multiorgan morbidities, such as intraventricular hemorrhage, retinopathy of prematurity, bronchopulmonary dysplasia, and necrotizing enterocolitis. Experimental and clinical studies indicate that early supplementation with IGF-1 can improve growth in catabolic states and reduce brain injury after hypoxic/ischemic events. A multicenter phase II study is currently underway to determine whether intravenous replacement of human recombinant IGF-1 up to normal intrauterine serum concentrations can improve growth and development and reduce prematurity-associated morbidities