Effects of nasal continuous positive airway pressure (NCPAP) on breathing pattern in spontaneously breathing premature newborn infants

OBJECTIVE: The aim of the study was to assess the influence of nasal continuous positive airway pressure (NCPAP) on breathing pattern in preterm newborns. DESIGN: Prospective study. SETTING: Neonatal intensive care unit. PATIENTS: Ten premature newborn infants on NCPAP (gestational age range from 27 to 32 weeks, mean birth weight 1300+/-460 g) admitted in our neonatal intensive care unit (NICU) for respiratory distress syndrome. METHODS: Breathing patterns and changes in lung volumes level were obtained using respiratory inductive plethysmography (RIP), at random CPAP levels (0, 2, 4, 6 and 8 cmH2O). Raw data were analysed for end-expiratory lung volume level (EELV-level), tidal volume (Vt), respiratory rate, phase angle and labour breathing index (LBI). RESULTS: CPAP increased EELV-level by 2.1+/-0.3xVt from 0 to 8 cmH2O ( p<0.01). Vt increased by 43% from CPAP of 0 cmH2O to CPAP of 8 cmH2O ( p<0.01). We also found that CPAP lowered the phase angle (from 76+/-21 degrees at CPAP of 0 cmH2O to 30+/-15 degrees at CPAP of 8 cmH2O; p<0.01 ) and LBI (from 1.7+/-0.8 at CPAP of 0 cmH2O to 1.2+/-0.3 at CPAP of 8 cmH2O; p<0.05). CONCLUSION: NCPAP improves the breathing strategy of premature infants with respiratory failure, as reflected by improved thoraco-abdominal synchrony, increased Vt and reduction of the LBI. This effect is associated with an increase in EELV-level with CPAP level. However, further investigations are necessary to establish the best CPAP level that ensures both safety and efficiency.     

Does smoking in pregnancy modify the impact of antenatal steroids on neonatal respiratory distress syndrome? Results of the Epipage study

OBJECTIVES: To assess the relation between cigarette smoking during pregnancy and neonatal respiratory distress syndrome (RDS) in very preterm birth, and to analyse the differential effect of antenatal steroids on RDS among smokers and non-smokers. DESIGN: A population based cohort study (the French Epipage study). SETTING: Regionally defined births in France. METHODS: A total of 858 very preterm liveborn singletons (27-32 completed weeks of gestation) of the French Epipage study were included in this analysis. The odds ratio for RDS in relation to smoking in pregnancy was estimated using a logistic regression to control for gestational age. The odds ratio for RDS in relation to antenatal steroids was estimated taking into account an interaction between antenatal steroids and cigarette smoking, using multiple logistic regression to control for gestational age, birthweight ratio, main causes of preterm birth, mode of delivery, and sex. RESULTS: The odds ratio for RDS in relation to smoking in pregnancy adjusted for gestational age (aOR) was 0.59 (95% confidence interval (CI) 0.44 to 0.79). The aOR for RDS in relation to antenatal steroids was 0.31 (95% CI 0.19 to 0.49) in babies born to non-smokers and 0.63 (95% CI 0.38 to 1.05) in those born to smokers; the difference was significant (p = 0.04). CONCLUSIONS: Cigarette smoking during pregnancy is associated with a decrease in the risk of RDS in very preterm babies. Although antenatal steroids reduce the risk of RDS in babies born to both smokers and non-smokers, the reduction is smaller in those born to smokers.     

From the Cover: Ryanodine receptor fragmentation and sarcoplasmic reticulum Ca2+ leak after one session of high-intensity interval exercise

High-intensity interval training (HIIT) is a time-efficient way of improving physical performance in healthy subjects and in patients with common chronic diseases, but less so in elite endurance athletes. The mechanisms underlying the effectiveness of HIIT are uncertain. Here, recreationally active human subjects performed highly demanding HIIT consisting of 30-s bouts of all-out cycling with 4-min rest in between bouts (≤3 min total exercise time). Skeletal muscle biopsies taken 24 h after the HIIT exercise showed an extensive fragmentation of the sarcoplasmic reticulum (SR) Ca²⁺ release channel, the ryanodine receptor type 1 (RyR1). The HIIT exercise also caused a prolonged force depression and triggered major changes in the expression of genes related to endurance exercise. Subsequent experiments on elite endurance athletes performing the same HIIT exercise showed no RyR1 fragmentation or prolonged changes in the expression of endurance-related genes. Finally, mechanistic experiments performed on isolated mouse muscles exposed to HIIT-mimicking stimulation showed reactive oxygen/nitrogen species (ROS)-dependent RyR1 fragmentation, calpain activation, increased SR Ca²⁺ leak at rest, and depressed force production due to impaired SR Ca²⁺ release upon stimulation. In conclusion, HIIT exercise induces a ROS-dependent RyR1 fragmentation in muscles of recreationally active subjects, and the resulting changes in muscle fiber Ca²⁺-handling trigger muscular adaptations. However, the same HIIT exercise does not cause RyR1 fragmentation in muscles of elite endurance athletes, which may explain why HIIT is less effective in this group.It is increasingly clear that regular physical exercise plays a key role in the general well-being, disease prevention, and longevity of humans. Impaired muscle function manifesting as muscle weakness and premature fatigue development are major health problems associated with the normal aging process as well as with numerous common diseases (1). Physical exercise has a fundamental role in preventing and/or reversing these muscle problems, and training also improves the general health status in numerous diseases (2–4). On the other side of the spectrum, excessive muscle use can induce prolonged force depressions, which may set the limit on training tolerance and performance of top athletes (5, 6).Recent studies imply a key role of the sarcoplasmic reticulum (SR) Ca²⁺ release channel, the ryanodine receptor 1 (RyR1), in the reduced muscle strength observed in numerous physiological conditions, such as after strenuous endurance training (6), in situations with prolonged stress (7), and in normal aging (8, 9). Defective RyR1 function is also implied in several pathological states, including generalized inflammatory disorders (10), heart failure (11), and inherited conditions such as malignant hyperthermia (12) and Duchenne muscular dystrophy (13). In many of the above conditions, there is a link between the impaired RyR1 function and modifications induced by reactive oxygen/nitrogen species (ROS) (6, 8, 10, 12, 13). Conversely, altered RyR1 function may also be beneficial by increasing the cytosolic free [Ca²⁺] ([Ca²⁺]_i) at rest, which can stimulate mitochondrial biogenesis and thereby increase fatigue resistance (14–16). Intriguingly, effective antioxidant treatment hampers beneficial adaptations triggered by endurance training (17–19), and this effect might be due to antioxidants preventing ROS-induced modifications of RyR1 (20).A high-intensity interval training (HIIT) session typically consists of a series of brief bursts of vigorous physical exercise separated by periods of rest or low-intensity exercise. A major asset of HIIT is that beneficial adaptations can be obtained with much shorter exercise duration than with traditional endurance training (21–25). HIIT has been shown to effectively stimulate mitochondrial biogenesis in skeletal muscle and increase endurance in untrained and recreationally active healthy subjects (22, 26), whereas positive effects in elite endurance athletes are less clear (21, 27, 28). Moreover, HIIT improves health and physical performance in various pathological conditions, including cardiovascular disease, obesity, and type 2 diabetes (29, 30). Thus, short bouts of vigorous physical exercise trigger intracellular signaling of large enough magnitude and duration to induce extensive beneficial adaptations in skeletal muscle. The initial signaling that triggers these adaptations is not known.In this study, we tested the hypothesis that a single session of HIIT induces ROS-dependent RyR1 modifications. These modifications might cause prolonged force depression due to impaired SR Ca²⁺ release during contractions. Conversely, they may also initiate beneficial muscular adaptations due to increased SR Ca²⁺ leak at rest.     

Treatment strategies for neonatal pulmonary morbidity in Europe]

OBJECTIVES: To survey practices in 14 European countries and to describe strategies for the prevention and treatment of pulmonary morbidity in very preterm newborns. METHODS: Questionnaires covering the use of prenatal steroids, surfactant and postnatal steroids were sent in 1999-2000 to every neonatal unit taking very preterm newborns in charge in population-based areas covering at least 20,000 births annually. One questionnaire was sent by surveyed unit. RESULTS: Results are given concerning these three treatments and compared to evidence based recommendations. CONCLUSION: Antenatal steroids were given at recommended terms. Surfactant was prescribed with respect of best practices. Postnatal steroids utilisation was not well described.     

Motor-neuron-disease-like phenotype associated with IgLON5 disease

Journal of Neurology - A growing spectrum of neurological manifestations are being recognized in association with IgLON5 autoimmunity, including recent reports of motor-neuron-disease-like...     

Palivizumab administration in preterm infants in France: EPIPAGE-2 cohort study

Background

Several countries, including France, have restricted the indications for monoclonal antibodies directed against respiratory syncytial virus (RSV) compared to the marketing authorization (MA). No new data concerning use of palivizumab on a national scale have been published since the 2007 update of the national guidelines.

Dynamic study of the changes in the composition of fatty acids in serum lipid fractions under a diet rich in polyunsaturated fatty acids

Appropriate adjustment of diet and specially reduction of the saturated fatty acids content is the cornerstone of correcting many hyperlipidemias. What we have tried in our study was first to show the evolution of the changes in the serum's fatty acids composition under a rich polyunsaturated fatty acids diet, second to find an index proving that the diet had correctly been taken. Chromatographic analysis were performed after ultracentrifugal separation of the lipoprotein fractions. Seven volunteers, non fat, and normolipemics were selected. Samples were collected every three or five days before and during the diet. The whole test lasted twenty days. What had been shown is that the linoleic acid content increased but the one of the oleic acid decreased in all lipoprotein fractions. Those changes are bestly illustrated by using the (formula: see text) ratio as a kinetic index. The triglycerid fraction modifications are faster than the phospholipid's one. Concerning the other fatty acids, the modifications are less spectacular : the palmitic acid decrease in every lipids fractions and the palmitoleic acid has a significant decrease only in the esterified cholesterol. And the stearic acid has no variation at least significatively.