Diaphragmatic and excursion thickness in newborns using diaphragmatic kinesiology ultrasound: an observational study / Espessura e excursão diafragmática em recém-nascidos usando ultrassonografia cinesiológica do diafragma: um estudo observacional

Abstract Introduction The study of the diaphragm muscle has aroused the interest of physiotherapists who work with kinesiological ultrasonography, but still little explored; however, its findings can contribute to the clinical practice of hospitalized patients in neonatal intensive care units. Objective To measure the excursion and thickening of the diaphragm and describe measurements among neonates, preterm, and full-term. Methods Diaphragmatic kinesiological ultrasonography was performed on hospitalized newborns, in Neonatal Unit Care Unit, placed in supine position in their own bed, on the sixth day of life. Three repeated measurements of the same respiratory cycle were made, both for excursion and for diaphragmatic thickening. Results 37 newborns participated in the study and 25 were premature. The mean weight at the time of collection was 2,307.0 ± 672.76 grams and the gestational age was 35.7 ± 3.3 weeks. Diaphragmatic excursion increased with increasing gestational age (p = 0.01, df = 0.21) in term infants (p = 0.17, df = 0.35). Conclusion There was a positive correlation between diaphragmatic excursion and gestational age. There was no statistically significant difference in the measurements of excursion and inspiratory diaphragm thickening between preterm and term newborns, although pointing to higher measurements in the latter group.

Resumo Introdução O estudo do músculo diafragma tem des-pertado o interesse dos fisioterapeutas que trabalham com ultrassonografia cinesiológica. Ainda pouco explo-rado, contudo, seus achados podem contribuir para a prática clínica dos pacientes internados em unidades de terapia intensiva neonatal (UTIN). Objetivo Mensurar a excursão e o espessamento diafragmático e descrever as medidas entre recém-nascidos prematuros e a termo. Métodos Realizou-se ultrassonografia cinesiológica diafragmática em recém-nascidos internados em UTIN, posicionados em supino em seu próprio leito, no sexto dia de vida. Foram realizadas três medidas repetidas do mesmo ciclo respiratório, tanto da excursão quanto do espessamento diafragmático. Resultados Participaram do estudo 37 recém-nascidos, dos quais 25 eram pre-maturos. O peso no momento da coleta foi de 2.307,0 ± 672,76 gramas e a idade gestacional foi de 35,7 ± 3,3 semanas. A excursão diafragmática aumentou de acordo com o aumento da idade gestacional (p = 0,01; df = 0,21). A espessura variou entre 0,10 e 0,16 cm durante a inspiração nos prematuros e entre 0,11 e 0,19 cm nos nascidos a termo (p = 0,17; df = 0,35). Conclusão Houve correlação positiva entre a excursão diafragmá-tica e a idade gestacional. Não observou-se diferença estatisticamente significativa das medidas de excursão e de espessamento diafragmático inspiratório entre recém-nascidos prematuros e recém-nascidos a termo, embora apontando para maiores medidas neste último grupo.

Admission hypothermia, neonatal morbidity, and mortality: evaluation of a multicenter cohort of very low birth weight preterm infants according to relative performance of the center.

This prospective cohort study aimed to assess the association of admission hypothermia (AH) with death and/or major neonatal morbidities among very low birth weight (VLBW) preterm infants based on the relative performance of 20 centers of the Brazilian Network of Neonatal Research. This is a retrospective analysis of prospectively collected data using the database registry of the Brazilian Network on Neonatal Research. Center performance was defined by the relative mortality rate using conditional inference trees. A total of 4356 inborn singleton VLBW preterm infants born between January 2013 and December 2016 without malformations were included in this study. The centers were divided into two groups: G1 (with lower mortality rate) and G2 (with higher mortality rate). Crude and adjusted relative risks (RR) and 95% confidence intervals (95%CI) were estimated by simple and multiple log-binomial regression models. An AH rate of 53.7% (19.8-93.3%) was significantly associated with early neonatal death in G1 (adjusted RR 1.41, 95% CI 1.09-1.84) and G2 (adjusted RR 1.29, 95%CI 1.01-1.65) and with in-hospital death in G1 (adjusted RR 1.29, 95%CI 1.07-1.58). AH was significantly associated with a lower frequency of necrotizing enterocolitis (adjusted RR 0.58, 95%CI 38-0.88) in G2.Conclusion: AH significantly associated with early neonatal death regardless of the hospital performance. In G2, an unexpected protective association between AH and necrotizing enterocolitis was found, whereas the other morbidities assessed were not significantly associated with AH. What is Known: • Admission hypothermia is associated with early neonatal death. • The association of admission hypothermia with major neonatal morbidities has not been fully established. What is New: • Admission hypothermia was significantly associated with early neonatal and in-hospital death in centers with the lowest relative mortality rates. • Admission hypothermia was not associated with major neonatal morbidities and with in-hospital death but was found to be a protective factor against necrotizing colitis in centers with the highest relative mortality rates.

Leptin resistance is not the primary cause of weight gain associated with reduced sex hormone levels in female mice.

Several studies have shown that estrogens mimic leptin's effects on energy balance regulation. However, the findings regarding the consequences of reduced sex hormone levels on leptin sensitivity are divergent. In the present study, we employed different experimental paradigms to elucidate the interaction between estrogens, leptin, and energy balance regulation. We confirmed previous reports showing that ovariectomy caused a reduction in locomotor activity and energy expenditure leading mice to obesity and glucose intolerance. However, the acute and chronic anorexigenic effects of leptin were preserved in ovariectomized (OVX) mice despite their increased serum leptin levels. We studied hypothalamic gene expression at different time points after ovariectomy and observed that changes in the expression of genes involved in leptin resistance (suppressors of cytokine signaling and protein-tyrosine phosphatases) did not precede the early onset of obesity in OVX mice. On the contrary, reduced sex hormone levels caused an up-regulation of the long form of the leptin receptor (LepR), resulting in increased activation of leptin signaling pathways in OVX leptin-treated animals. The up-regulation of the LepR was observed in long-term OVX mice (30 d or 24 wk after ovariectomy) but not 7 days after the surgery. In addition, we observed a progressive decrease in the coexpression of LepR and estrogen receptor-α in the hypothalamus after the ovariectomy, resulting in a low percentage of dual-labeled cells in OVX mice. Taken together, our findings suggest that the weight gain caused by reduced sex hormone levels is not primarily caused by induction of a leptin-resistance state.

Estradiol modulates Kiss1 neuronal response to ghrelin.

Ghrelin is a metabolic signal regulating energy homeostasis. Circulating ghrelin levels rise during starvation and fall after a meal, and therefore, ghrelin may function as a signal of negative energy balance. Ghrelin may also act as a modulator of reproductive physiology, as acute ghrelin administration suppresses gonadotropin secretion and inhibits the neuroendocrine reproductive axis. Interestingly, ghrelin's effect in female metabolism varies according to the estrogen milieu predicting an interaction between ghrelin and estrogens, likely at the hypothalamic level. Here, we show that ghrelin receptor (GHSR) and estrogen receptor-α (ERα) are coexpressed in several hypothalamic sites. Higher levels of circulating estradiol increased the expression of GHSR mRNA and the coexpression of GHSR mRNA and ERα selectively in the arcuate nucleus (ARC). Subsets of preoptic and ARC Kiss1 neurons coexpressed GHSR. Increased colocalization was observed in ARC Kiss1 neurons of ovariectomized estradiol-treated (OVX + E2; 80%) compared with ovariectomized oil-treated (OVX; 25%) mice. Acute actions of ghrelin on ARC Kiss1 neurons were also modulated by estradiol; 75 and 22% of Kiss1 neurons of OVX + E2 and OVX mice, respectively, depolarized in response to ghrelin. Our findings indicate that ghrelin and estradiol may interact in several hypothalamic sites. In the ARC, high levels of E2 increase GHSR mRNA expression, modifying the colocalization rate with ERα and Kiss1 and the proportion of Kiss1 neurons acutely responding to ghrelin. Our findings indicate that E2 alters the responsiveness of kisspeptin neurons to metabolic signals, potentially acting as a critical player in the metabolic control of the reproductive physiology.