Somatostatin levels during infancy, pregnancy, and lactation: a review

Pancreatic islet adaptation in pregnancy and postpartum

Pancreatic islets, particularly insulin-producing β-cells, are central regulators of glucose homeostasis capable of responding to a variety of metabolic stressors. Pregnancy is a unique physiological stressor, necessitating the islets to adapt to the complex interplay of maternal and fetal-placental factors influencing the metabolic milieu. In this review we highlight studies defining gestational adaptation mechanisms within maternal islets and emerging studies revealing islet adaptations during the early postpartum and lactation periods. These include adaptations in both β and in 'non-β' islet cells. We also discuss insights into how gestational and postpartum adaptation may inform pregnancy-specific and general mechanisms of islet responses to metabolic stress and contribute to investigation of gestational diabetes.

New insights in pediatrics in 2021: choices in allergy and immunology, critical care, endocrinology, gastroenterology, genetics, haematology, infectious diseases, neonatology, neurology, nutrition, palliative care, respiratory tract illnesses and telemedicine

In this review, we report the developments across pediatric subspecialties that have been published in the Italian Journal of Pediatrics in 2021. We highlight advances in allergy and immunology, critical care, endocrinology, gastroenterology, genetics, hematology, infectious diseases, neonatology, neurology, nutrition, palliative care, respiratory tract illnesses and telemedicine.

Dietary treatment of congenital chylothorax with skimmed breast milk

BACKGROUND

Congenital chylothorax (CC) is a rare but potentially life-threatening condition in newborns. It is defined as an accumulation of chyle in the pleural cavity. The few publications regarding medical management and therapeutic dietary intervention motivated us to share our experience.

METHODS

Neonates diagnosed with congenital chylothorax and treated at Innsbruck Medical University Hospital between 2013 and 2020 (n = 6, gestational age: 36 3/7, 32 5/7, 36 4/7, 35 0/7, 35 4/7, 37 3/7 weeks) were eligible for this report. The cornerstones of treatment for chylothorax conventionally consist of chest tube drainage (CTD), respiratory support, dietary restriction of long-chain triglycerides (LCT) or total parenteral nutrition (TPN). In further course the introduction of a medium-chain triglyceride (MCT)-based formula followed by an overlapping switch to a formula with low LCT and high MCT, containing the essential long-chain fatty acids (LCFA), is attempted. In three patients we used fat-modified (skimmed) breast milk to provide a high protein and low fat diet and to avoid the discontinuation of breast milk.

RESULTS

The outcome of an early introduction of LCFA in the form of skimmed breast milk after resolution of chylothorax diverse. One patient had a favourable outcome, meaning no recurrence of pleural effusion, adequate weight gain and a content mother, while another patient had a relapse of pleural effusion after the administration of skimmed milk and was therefore transitioned back to Basic F® . The CC of patient 5 was difficult due to Noonan syndrome. Two weeks after the introduction of skimmed breast milk the mother wanted to stop to express breast milk, so nutrition was changed to Basic F®.

CONCLUSION

The first-line therapy of chylothorax is a combination of respiratory stabilization and dietary modification. The use of skimmed breast milk is advisable in CC and feasible by means of a simple milk defatting procedure. It offers benefits to mothers who wish to resume breast feeding after resolution of chylothorax and has proven positive effects, above all in preterm infants as optimal nutrition with protective components superior to formula feeding. However, the nutritional analysis of the skimmed milk and the correlation to a re-accumulation of pleural fluid remains a question to be answered.

Endocrine cell lines from the placenta

Cell-lines derived from human placenta and chorion have been used extensively to model the endocrine functions of human trophoblast. In general terms, the endocrine functions of the primary cells and tissues are at least partially replicated within the cell-lines, suggesting that they may be used as appropriate models. There are, however, two major provisos that compromise this generalisation. Firstly, the endocrine function of placenta represents a complex interaction between cytotrophoblast, syncytiotrophoblast and multiple regulators, so a single cell population digested from the normal environment is unlikely to represent this. Secondly, the characterisation of primary trophoblast populations and of cell-lines is incomplete, complicating the assignment of functions to trophoblast populations. Despite these difficulties, useful information has been obtained from the available cell-lines, regardless of whether they have arisen spontaneously, been transformed in vitro, or derived from cancers in vivo.

A CCK(A)-receptor antagonist administered to the neonate alters mother-infant interactions in the rat

The importance of the infant's cholecystokinin (CCK) system for eliciting optimal maternal care was examined in 6-9-day-old Sprague-Dawley rats. After administration of either vehicle, CCK-8 (1 or 8 microg/kg) or devazepide (1 mg/kg; a selective CCK(A) receptor antagonist), pups were either individually isolated (Experiment 1) or individually reunited with their dam (Experiment 2) and the rats' behavior was observed. When isolated, pups that received devazepide displayed significantly more head-lifting and wall-climbing attempts than vehicle-treated controls, suggesting that endogenous CCK dampens activity. Devazepide-treated rats were found more frequently in proximity with their mothers when reunited with them, and they emitted more ultrasonic vocalizations compared to vehicle controls. Pups treated with 1 microg/kg CCK received less body licking than vehicle controls. In addition, dams hovered and crouched over devazepide-treated pups more than over pups treated with 1 microg/kg CCK. The results suggest that endogenous CCK has a calming, quieting effect in the neonatal pup and that this, in turn, results in less infant-mother attractivity and reduced levels of maternal care.

Lactation and salt loading similarly alter neuropeptide Y, but differentially alter somatostatin, in separate sets of rat neural lobe axons

Neuropeptide Y (NPY) and somatostatin immunoreactivities are present in neural lobe axons of the rat pituitary. Both peptides are upregulated during lactation, because NPY gene expression increases in the hypothalamus and plasma concentrations of somatostatin are elevated. However, the effects of lactation on NPY and somatostatin in the neural lobe are unknown. Although NPY immunoreactivity increases in the neural lobe following salt loading of male rats, the somatostatin response is unknown. To answer these questions, NPY and somatostatin immunoreactivities in the neural lobe were examined during lactation and salt loading using immunohistochemistry and image analysis. On day 2 of lactation, the area covered by immunoreactivity, a combined measurement of axon density and size of axonal swellings, of both NPY and somatostatin increased compared to ovariectomized rats. The increase in NPY was four- to fivefold greater than that of somatostatin. By day 10 of lactation, values returned to those of ovariectomized rats. Following 10 days of salt loading, the area covered by NPY immunoreactivity increased approximately 10-fold over control male rats, whereas somatostatin remained unchanged. NPY and somatostatin were not colocalized in neural lobe axons in either paradigm, demonstrating that two different neuronal populations were involved in both cases. These data indicate that NPY and somatostatin were regulated similarly during lactation, but differentially following salt loading.