Extrauterine Life Research Articles

Physiological fetal vascular shunts and failure to regress: what the radiologist needs to know.

The fetal circulation is characterized by the presence of three physiological vascular shunts - the ductus arteriosus, the foramen ovale and the ductus venosus. Acting in concert, these shunts preferentially stream blood flow in a pattern that maximizes efficiency of blood oxygenation by the maternofetal unit. Shortly following the transition to extrauterine life, a quick and predetermined succession of events results in closure of these embryological structures with consequent establishment of postnatal vascular flow patterns. While this transition is often seamless, the physiological shunts of the fetus occasionally fail to regress. Such failure to regress can occur in isolation or in association with other congenital malformations. This failed regression challenges the circulatory physiology of the neonate and might have implications for the optimum functioning of several organ systems. When symptomatic, these shunts are treated. Interventions, when undertaken, might be medical, endovascular or surgical. The radiologist's role continues to expand in the assessment of these shunts, in providing a roadmap for treatment and in prompt identification of treatment-related complications. This review is to familiarize radiologists with the embryology, pre- and post-treatment imaging appearances, and associated complications of persistent fetal vascular shunts.

Regional pulmonary oxygen saturations immediately after birth

BackgroundPartial oxygen saturation (SpO2) increases within minutes during transition from the intrauterine to extrauterine life. This study aims to determine the postnatal course of pulmonary regional oxygen saturation (rSO2) measured by Near-Infrared Spectroscopy (NIRS). MethodsWe conducted an observational study at the delivery room in infants above 35 weeks of gestation who did not need resuscitation and did not develop respiratory distress. Preductal pulse oximetry (Covidien NellcorTM) and right pulmonary apex oxygen saturation (raSO2) and basal oxygen saturation (rbSO2) (Covidien INVOSTM) were measured, starting from the postnatal third minute of life, until the 15th minute. The correlations between SpO2 and pulmonary rSO2 were analyzed. ResultsOf the 110 infants included in the study, 87 were term and 23 were late preterms. The gestational age and birth weight were 38.5 ± 1.36 weeks and 3285 ± 508 g, respectively. Median (5th–95th percentile) raSO2 and rbSO2 were 79% (58–95%) and 78% (46–95%) at the third minute, respectively. The rSO2 values measured from both sides increased and reached a steady-state around postnatal 9 min, similar to SpO2 values. The pulmonary NIRS values were significantly higher for babies born by C-Section compared to babies born by vaginal delivery (p < 0.05). ConclusionWe found that rSO2 measurements increased within minutes in the postnatal period in late preterm and term babies without respiratory distress and reached a plateau at the postnatal 9th minute. The normal values obtained from this preliminary study may be used to predict the prognosis of cases with respiratory distress.

Histopathologic Impacts of Diabetes Mellitus on Umbilical Cord During Pregnancy.

As a feto-maternal connection route, the umbilical cord is an important determinant of fetal well-being. The umbilical vessels, unlike major vessels, are not fed by the vasa vasorum, making them more vulnerable to hemodynamic changes induced by maternal diseases such as diabetes mellitus. Furthermore, it may be discarded for exacerbating any perinatal illness. The umbilical cord is the major supporter of a successful neonatal prognosis, since it is the sole organ that initiates life. It plays the most important role in feto-placental relation, as well as what will happen to the infant on extra-uterine life. As a result, the histopathologic alterations in the umbilical cord associated with gestational diabetes mellitus were examined in this review study.

CARE OF NEW BORN INFANTS ACCORDING TO THE CULTURAL PERSPECTIVE OF THE BATAK TOBA TRIBE IN HUTA BAYU RAJA DISTRICT

Newborn (neonatal) is the first 28 days of human life. At this time there is a process of adjusting the baby's body system from intra-uterine life to extra-uterine life. This is the period that needs extra attention and care because this is the period when the mortality rate is the highest. The culture of the Toba Batak tribe has certain traditions that have been applied from generation to generation until now in terms of caring for newborns. This study uses a qualitative phenomenological design which aims to find out and dig deeper about newborn care according to the cultural perspective of the Toba Batak tribe in Huta Bayu Raja District, Simalungun Regency. Data collection was carried out from January 10 2014 to March 28 2014 using purposive sampling with a sample of five participants. The data collection process was carried out by in-depth interviews using a tape recorder. The results showed that care for newborns according to the Toba Batak cultural perspective consisted of organ care, umbilical cord care, hygiene and skin care, gastrointestinal care, maintaining temperature and warming the baby's body, fulfillment of nutrition, giving immunity, and other special care, namely marempas, maresek-esek and giving small amounts (blessings). The results of this study are expected to be used as knowledge and information material for nurses in getting to know the culture of the Toba Batak tribe and planning comprehensive nursing care related to newborn care. This culture must also be filtered because there is a culture that has a negative impact on the health of the baby, and it is necessary to provide counseling related to the care of newborns.

Epicardial fat thickness in infants of diabetic mothers.

Epicardial fat thickness (EFT) in adults and children has been related to the metabolic syndrome and other cardiovascular risk factors; however, scarce studies have evaluated it in infants of diabetic mothers (IDM) in whom, alterations in the thickness of the interventricular septum have been reported. This study compares the EFT in IDM versus infants of non-diabetic mothers (INDM) and its association with others echocardiographic parameters. We performed a cross sectional study in 93 infants (64 IDM and 29 INDM). To evaluate EFT dimensions, an echocardiogram was performed within the first 24h of extrauterine life in both groups. In diabetic mothers, HbA1c was also determined. There was no significant difference in birth weight between the groups although gestational age was lower in IDM. The EFT (3.6 vs. 2.5 mm, p < 0.0001), the interventricular septum thickness (IVST) (6.2 vs. 5.2 mm, p < 0.0001) and the IVST / left ventricle posterior wall (1.3 vs. 1.1, p = 0.001) were higher in the IDM; while the left ventricular expulsion fraction [LVFE] (71.1 vs. 77.8; p < 0.0001) was lower than in the INDM, respectively. We found a positive correlation between EFT with IVST (r = 0.577; p = 0.0001), LVPW (r = 0.262; p = 0.011), IVST/LVPW index (r = 0.353; p = 0.001), and mitral integral early velocity (r = 0.313; p = 0.002), while a negative correlation with LVFE was observed (r = -0.376; p = 0.0001). The EFT is higher in IDM than in INDM. It was positively related with echocardiographic parameters of left ventricular thickness and negatively with left ventricular ejection function.

The imprinted Zdbf2 gene finely tunes control of feeding and growth in neonates.

Genomic imprinting refers to the mono-allelic and parent-specific expression of a subset of genes. While long recognized for their role in embryonic development, imprinted genes have recently emerged as important modulators of postnatal physiology, notably through hypothalamus-driven functions. Here, using mouse models of loss, gain and parental inversion of expression, we report that the paternally expressed Zdbf2 gene controls neonatal growth in mice, in a dose-sensitive but parent-of-origin-independent manner. We further found that Zdbf2-KO neonates failed to fully activate hypothalamic circuits that stimulate appetite, and suffered milk deprivation and diminished circulating Insulin Growth Factor 1 (IGF-1). Consequently, only half of Zdbf2-KO pups survived the first days after birth and those surviving were smaller. This study demonstrates that precise imprinted gene dosage is essential for vital physiological functions at the transition from intra- to extra-uterine life, here the adaptation to oral feeding and optimized body weight gain.

Diagnostic Value of Skin Manifestations in Neonates in First 72 Hours of Birth

Background: Newborn skin undergo various stages of developmental changes after birth in order to adapt to challenging conditions of extrauterine life. Many dermatoses though appearing challenging could actually be momentary or physiological undergoing rapid involution, therefore, a vital knowledge of neonatal skin biology is essential for all dermatologists. Aim: To study the clinical pattern of various dermatoses in neonates and their diagnostic value. Study design: Descriptive cross sectional study Place and duration of study: Department of Paediatrics, HIT Hospital Taxila from 1st April 2021 to 30th September 2021. Methodology: One hundred neonates within first 72 hours of life regardless of gestational age, sex and mode of delivery were selected. Neonates kept in intensive care unit were not included, as the chances of infection and sepsis are more in them. A detailed history was taken. Dermatological examination of all the neonates was done thoroughly in broad day light to accurately define the morphology of skin lesions. In all instances, the diagnosis of skin lesion was exclusively based upon the clinical impression. Results: There were 42 (42%) males and 58 (58%) females. 74% were full term and 26% were preterm,79% had normal birth weight (2.5-3.5 kg) and 21% had low birth weight (&lt;2.5kg). Cutaneous findings were positive in 87 (87%). 79% had normal physiological cutaneous manifestations and transient skin changes and only 8% had pathological skin changes. Conclusion: Majority of the skin manifestation within 72 hours after birth are either physiological or benign that last for sometimes. Key words: Neonate, Skin manifestations, Prevalence

Comparison of insulin sensitivity between healthy neonatal foals and horses using minimal model analysis.

The equine neonate is considered to have impaired glucose tolerance due to delayed maturation of the pancreatic endocrine system. Few studies have investigated insulin sensitivity in newborn foals using dynamic testing methods. The objective of this study was to assess insulin sensitivity by comparing the insulin-modified frequently sampled intravenous glucose tolerance test (I-FSIGTT) between neonatal foals and adult horses. This study was performed on healthy neonatal foals (n = 12), 24 to 60 hours of age, and horses (n = 8), 3 to 14 years of age using dextrose (300 mg/kg IV) and insulin (0.02 IU/kg IV). Insulin sensitivity (SI), acute insulin response to glucose (AIRg), glucose effectiveness (Sg), and disposition index (DI) were calculated using minimal model analysis. Proxy measurements were calculated using fasting insulin and glucose concentrations. Nonparametric statistical methods were used for analysis and reported as median and interquartile range (IQR). SI was significantly higher in foals (18.3 L·min-1· μIU-1 [13.4–28.4]) compared to horses (0.9 L·min-1· μIU-1 [0.5–1.1]); (p < 0.0001). DI was higher in foals (12 × 103 [8 × 103−14 × 103]) compared to horses (4 × 102 [2 × 102−7 × 102]); (p < 0.0001). AIRg and Sg were not different between foals and horses. The modified insulin to glucose ratio (MIRG) was lower in foals (1.72 μIUinsulin2/10·L·mgglucose [1.43–2.68]) compared to horses (3.91 μIU insulin2/10·L·mgglucose [2.57–7.89]); (p = 0.009). The homeostasis model assessment of beta cell function (HOMA-BC%) was higher in horses (78.4% [43–116]) compared to foals (23.2% [17.8–42.2]); (p = 0.0096). Our results suggest that healthy neonatal foals are insulin sensitive in the first days of life, which contradicts current literature regarding the equine neonate. Newborn foals may be more insulin sensitive immediately after birth as an evolutionary adaptation to conserve energy during the transition to extrauterine life.

Neonatal amygdala resting-state functional connectivity and socio-emotional development in very preterm children.

Very preterm children are more likely to exhibit difficulties in socio-emotional processing than their term-born peers. Emerging socio-emotional problems may be partly due to alterations in limbic system development associated with infants’ early transition to extrauterine life. The amygdala is a key structure in this system and plays a critical role in various aspects of socio-emotional development, including emotion regulation. The current study tested the hypothesis that amygdala resting-state functional connectivity at term-equivalent age would be associated with socio-emotional outcomes in childhood. Participants were 129 very preterm infants (<33 weeks' gestation) who underwent resting-state functional MRI at term and received a neurodevelopmental assessment at 4–7 years (median = 4.64). Using the left and right amygdalae as seed regions, we investigated associations between whole-brain seed-based functional connectivity and three socio-emotional outcome factors which were derived using exploratory factor analysis (Emotion Moderation, Social Function and Empathy), controlling for sex, neonatal sickness, post-menstrual age at scan and social risk. Childhood Emotion Moderation scores were significantly associated with neonatal resting-state functional connectivity of the right amygdala with right parahippocampal gyrus and right middle occipital gyrus, as well as with functional connectivity of the left amygdala with the right thalamus. No significant associations were found between amygdalar resting-state functional connectivity and either Social Function or Empathy scores. The current findings show that amygdalar functional connectivity assessed at term is associated with later socio-emotional outcomes in very preterm children.

Is dexamethasone a good idea when we talk about caesarean delivery?

Respiratory distress syndrome is one of the most frequently researched and always of immediate interest topics, re­pre­sen­ting one of the main causes of morbidity and mortality in the neonatal population. Therefore, the antenatal ad­mi­nis­tration of corticosteroids in preterm births (between the 24th week and the 34th week of gestational age) is one of the most important antenatal therapies available, with a positive influence on the long-term neonatal prognosis. The effects on both the interstitium and other organs re­duce the risk of respiratory distress syndrome, necrotizing enterocolitis and intracranial hemorrhage. Scientific data about corticosteroid use in women at risk for preterm birth under 34 weeks of gestation and the benefits on the new­born adaptation to the extrauterine life, especially when it comes to caesarean delivery, are abundant. Of course, the benefit of corticoprophylaxis versus the possible long-term results on neurodevelopment, especially in school age, in this category of newborns should be considered. Among early-terms and full-term newborns, delivered by caesarean section, the pathophysiology of respiratory distress is closely related to the absorption of alveolar fluid and to the con­cen­tration of catecholamines in the fetal blood, and if there is no labor, these latter ones are affected. In this article, we present the observations obtained in a study conducted on 81 newborns from pregnancies with ages between 36 0/7 and 37 0/7 weeks, who received dexamethasone less than seven days before birth, conducted within the Obstetrics-Gynecology and Neonatology Clinic of the “Elias” University Emergency Hospital, Bucharest. We compared the results with data published in the field research, having as purpose to elucidate the controversies of antenatal corticosteroid therapy for various populations and, possibly, to establish individualized therapies.

From Intrauterine to Extrauterine Life—The Role of Endogenous and Exogenous Factors in the Regulation of the Intestinal Microbiota Community and Gut Maturation in Early Life

Differentiation of the digestive tube and formation of the gut unit as a whole, are regulated by environmental factors through epigenetic modifications which enhance cellular plasticity. The critical period of DNA imprinting lasts from conception until approximately the 1,000th day of human life. During pregnancy, besides agents that may directly promote epigenetic programming (e.g., folate, zinc, and choline supplementation), some factors (e.g., antibiotic use, dietary components) can affect the composition of the mother's microbiota, in turn affecting the fetal microbiome which interacts with the offspring's intestinal epithelial cells. According to available literature that confirms intrauterine microbial colonization, the impact of the microbiome and its metabolites on the genome seems to be key in fetal development, including functional gut maturation and the general health status of the offspring, as well as later on in life. Although the origin of the fetal microbiome is still not well-understood, the bacteria may originate from both the vagina, as the baby is born, as well as from the maternal oral cavity/gut, through the bloodstream. Moreover, the composition of the fetal gut microbiota varies depending on gestational age, which in turn possibly affects the regulation of the immune system at the barrier between mother and fetus, leading to differences in the ability of microorganisms to access and survive in the fetal environment. One of the most important local functions of the gut microbiota during the prenatal period is their exposure to foreign antigens which in turn contributes to immune system and tissue development, including fetal intestinal Innate Lymphoid Cells (ILCs). Additional factors that determine further infant microbiome development include whether the infant is born premature or at term, the method of delivery, maternal antibiotic use, and the composition of the mother's milk, among others. However, the latest findings highlight the fact that a more diverse infant gut microbiome at birth facilitates the proliferation of stem cells by microbial metabolites and accelerates infant development. This phenomenon confirms the unique role of microbiome. This review emphasizes the crucial perinatal and postnatal factors that may influence fetal and neonatal microbiota, and in turn gut maturation.

Assessment of serum amyloid A concentrations and biochemical profiles in lactating jennies and newborn Ragusano donkey foals around parturition and one month after foaling in Sicily.

A proper knowledge of biochemical parameters and inflammatory markers like serum amyloid A (SAA) is crucial in the monitoring of the first post‐partum period in equids. Since no information is available on SAA for donkeys at this stage, 50 animals including jennies (n.10) and newborn foals (n.10) within 48 hr from foaling, and jennies (n.10) and foals (n.20) after 30 days from parturition were enrolled in the study to assess routine biochemical profile including SAA. Jennies showed higher alkaline phosphatase and lower bilirubins and cholesterol at 30 days of lactation compared to post‐partum. Neonatal donkey foals showed significant higher concentrations of sodium, alkaline phosphatase, lactic dehydrogenase, blood urea nitrogen, creatinine and albumin within 48 hr of age, whilst higher values of phosphate and triglycerides were observed in older foals of 30 days of age. Significant higher SAA concentrations were recorded during the peripartum period in both jennies (25.95 ± 14.98 μg/ml) and newborn donkey foals (37.44 ± 19.75 μg/ml) compared to SAA values recorded in lactating jennies (2.38 ± 1.78 μg/ml) and in donkey foals (16.04 ± 18.14 μg/ml) at 30 days after parturition. The assessment of SAA in jennies and donkey foals around parturition and one month after foaling represents a valuable tool for the monitoring of health status during this stage when animals have to face with new challenges like the peak of lactation and extrauterine life adaptation respectively.

Dynamics of cortical oxygenation during immediate adaptation to extrauterine life

The neonatal transition involves physiological modifications as a consequence of the complexity of the perinatal period. Various strategies can be used to attain the same level of postnatal cerebral oxygenation, depending on the status of the infant at birth. We evaluated such strategies by recording 20 full-term newborns by near-infrared spectroscopy during the first 10 min of life. The acid–base status at birth revealed two clustered profiles of cerebral oxygenation dynamics. Lower pH and base excess and higher lactate levels were associated with more rapid attainment of the 95% maximal tissue oxygenation index value. These results suggest that metabolic mechanisms drive initial cerebral oxygenation dynamics during this critical period. These results confirm the capacity of newborns to develop multiple strategies to protect the brain.

Effect of Sildenafil on Mortality in Term Neonates with Hypoxemic Respiratory Failure due to Persistent Pulmonary Hypertension (SIPHON) - A Randomised Control Trial

Introduction: Persistent Pulmonary Hypertension (PPHN) complicates the transition from intrauterine to extrauterine life in some neonates. Sildenafil is known to reduce pulmonary pressures. However, its effect on reducing mortality is unclear. This study is conducted to determine the effect of Sildenafil in reducing all-cause mortality rate in term newborns with hypoxemic respiratory failure due to pulmonary hypertension. Methods: This was a double-blinded randomised control trial done in a level 3 neonatal intensive care unit. Term neonates on mechanical ventilation with an Oxygenation Index (OI) &gt; 15, and echocardiography suggesting PPHN were included in the study. The drug group received intravenous Sildenafil and the placebo group normal saline. The difference in the mortality rate between the two groups was analysed. Results: Eleven babies were randomised to the drug group and 12 to the placebo group. Both the groups matched in terms of their baseline characteristics. The difference in the drop of OI and right ventricular systolic pressure (RVSP) between the drug and placebo groups was not statistically significant. The relative risk of mortality was 0.436 in the intervention group (95% CI 0.105 to 1.80). The difference in the mortality rate was not statistically significant with P- value of 0.252. The rate of complications such as necrotising enterocolitis, sepsis, and pneumothorax was not different between the two groups. Conclusions: Intravenous sildenafil does not have any significant benefit over placebo in reducing all-cause mortality, oxygenation index, RVSP or complications when compared to placebo.

Innervated adrenomedullary microphysiological system to model nicotine and opioid exposure.

Transition to extrauterine life results in a surge of catecholamines necessary for increased cardiovascular, respiratory, and metabolic activity. Mechanisms mediating adrenomedullary catecholamine release are poorly understood. Important mechanistic insight is provided by newborns delivered by cesarean section or subjected to prenatal nicotine or opioid exposure, demonstrating impaired release of adrenomedullary catecholamines. To investigate mechanisms regulating adrenomedullary innervation, we developed compartmentalized 3D microphysiological systems (MPS) by exploiting GelPins, capillary pressure barriers between cell-laden hydrogels. The MPS comprises discrete cultures of adrenal chromaffin cells and preganglionic sympathetic neurons within a contiguous bioengineered microtissue. Using this model, we demonstrate that adrenal chromaffin innervation plays a critical role in hypoxia-mediated catecholamine release. Opioids and nicotine were shown to affect adrenal chromaffin cell response to a reduced oxygen environment, but neurogenic control mechanisms remained intact. GelPin containing MPS represent an inexpensive and highly adaptable approach to study innervated organ systems and improve drug screening platforms.

Dynamics of Deformation Properties of Erythrocytes in Wistar Rats during Postnatal Ontogeny.

We performed a detailed analysis of changes in the profiles of osmotic deformability using the method of gradient ektacytometry. Changes in all determinants that form the deformation properties of red blood cells in Wistar rats in the juvenile period and before puberty were determined. The dynamics of the formation of the rheological properties of the blood after birth is characterized by a wave-like change in the studied determinants. The changes are explained by adaptive reactions to extrauterine life as a result of hematopoiesis activation and the transition of the red bone marrow to a new level of functioning with the predominant replacement of physiological reticulocytosis in newborns with mature erythrocytes. The most critical period is from 10 days to 1 month after birth. Starting from the second month, the deformation parameters of erythrocytes are stabilized.

In water or on land? Evaluation of perinatal and neonatal outcomes of water births in low-risk women.

Evaluate perinatal and neonatal outcomes comparing a water birth to regular childbirth in low-risk women. File and methods: Retrospective analysis of a set of childbirths that took place over a given period of time in the hospital and health center of Haví&#345;ov. We compared a set of low-risk women that had given a water birth to a selected control group of low-risk women that had given regular childbirth. We evaluated statistical comparability, as well as perinatal and neonatal outcomes in both sets. From 1. 1. 2020 to 28. 2. 2021, 1,083 women gave birth in the delivery department of Haví&#345;ov hospital; from this set 122 were water births (11.3%). In our study, we only included 101 water deliveries (we designed our study to monitor low-risk births in order to be able to statistically correlate our findings; 21 water deliveries were excluded from our study due to perinatal risk factors - gestational diabetes and induced deliveries). We selected 60 low-risk women for our control group. Both sets of women were compared and we ruled out any statistically significant differences in age, education, body mass index, number of births given, gestation week at time of labor, number of smokers, premature rupture of membranes, women with previous history of one cesarean section, becoming pregnant by in vitro fertilization, presence of streptokoka skupiny B, and fetal weight. Water birth does not affect the Apgar score, neonatal adaptation to extra-uterine life, umbilical blood pH decrease, complications of infection, need of intensive care, and neonatal mortality. In the water birth set, we found increased occurrence of non-infectious conjunctivitis, treatable by regular eye drops without antibio-tics. We have not observed the effect of water birth on duration of the first and second stage of labor, total amount of uterotonics used, blood loss determined by the obstetrician, and uterine hypotonia. In the water birth group, we observed a prolonged third stage of delivery, lesser need for pharmacological stimulation (augmentation) of labor, notably lower use of analgesics, lower occurrence of birth injuries, shorter in-patient time, and more frequent bonding. We discovered that water birth does not increase the risk for mother and neonate in low-risk women. Despite initial concerns, our outcomes and mother satisfaction have clearly shown that water births are not only a temporary whim, but probably a new integral part of our obstetric care.

KNOWLEDGE ONESSENTIAL NEWBORN CARE AMONG POST NATAL MOTHERS

The birth of the baby is one of the wondrous moments in their life. A newborn is a continuum of foetal life and an important transient time to adopt extrauterine life. Essential Newborn care refers to the care provided by the mother or caregiver regarding breastfeeding, care o cord and eyes, maintaining body temperature, immunization, and controllingthe infection.Objectives: To assessthe knowledge level of postnatal mothers regarding Essential Newborn Care. Materials and methods: A non-experimental descriptive study was conducted in a selected hospital, Idukki to assess the knowledge of post-natal mothers regarding essential newborn care. A total of 50 post-natal mothers were selected with a non-probability convenience sampling technique. A quantitative research approach was used in this study. A self-structured questionnaire was used to gather the data, and appropriate statistics were performed to analyse the data. Results: The data results revealed that 50% of samples are in the age group of 19-27 yrs. and 50% were 28-36 years of age. The majority of the samples(72%) were Christians. Half of the samples(58%) were graduates and 22% were postgraduates. Concerning the level of knowledge, 10% of them had poor, 60% had average and 22% had good knowledge regarding essential newborn care.

Reawakening the Intrinsic Cardiac Regenerative Potential: Molecular Strategies to Boost Dedifferentiation and Proliferation of Endogenous Cardiomyocytes.

Despite considerable efforts carried out to develop stem/progenitor cell-based technologies aiming at replacing and restoring the cardiac tissue following severe damages, thus far no strategies based on adult stem cell transplantation have been demonstrated to efficiently generate new cardiac muscle cells. Intriguingly, dedifferentiation, and proliferation of pre-existing cardiomyocytes and not stem cell differentiation represent the preponderant cellular mechanism by which lower vertebrates spontaneously regenerate the injured heart. Mammals can also regenerate their heart up to the early neonatal period, even in this case by activating the proliferation of endogenous cardiomyocytes. However, the mammalian cardiac regenerative potential is dramatically reduced soon after birth, when most cardiomyocytes exit from the cell cycle, undergo further maturation, and continue to grow in size. Although a slow rate of cardiomyocyte turnover has also been documented in adult mammals, both in mice and humans, this is not enough to sustain a robust regenerative process. Nevertheless, these remarkable findings opened the door to a branch of novel regenerative approaches aiming at reactivating the endogenous cardiac regenerative potential by triggering a partial dedifferentiation process and cell cycle re-entry in endogenous cardiomyocytes. Several adaptations from intrauterine to extrauterine life starting at birth and continuing in the immediate neonatal period concur to the loss of the mammalian cardiac regenerative ability. A wide range of systemic and microenvironmental factors or cell-intrinsic molecular players proved to regulate cardiomyocyte proliferation and their manipulation has been explored as a therapeutic strategy to boost cardiac function after injuries. We here review the scientific knowledge gained thus far in this novel and flourishing field of research, elucidating the key biological and molecular mechanisms whose modulation may represent a viable approach for regenerating the human damaged myocardium.

Prognosticul fetal în operația cezariană

When deciding on a caesarean section, perinatologists should consider the consequences for the newborn. Studies show that caesarean section modifies adaptation to extrauterine life and is associated with risks of neonatal complications. Other determining factors for the condition and future of the newborn (gestational age, the existence of labor before cesarean section, anesthesia etc.) are not to be neglected. This article reviews the elements of the neonatal respiratory adaptation physiology, which are essential to understanding the clinical complications attributed to the mode of birth, and proposes a reconsideration of neonatal morbimortality after cesarean section.