Stabilisation and resuscitation with intact cord circulation is feasible using a wide variety of approaches; a scoping review.

AIM: This scoping review identified studies on approaches to intact cord resuscitation and/or stabilisation (ICR/S) for neonates delivered by Caesarean section (C-section). METHODS: A systematic literature search was carried out using the PubMed, Web of Science, Scopus, Cochrane and CINAHL databases to identify papers published in English from inception to 14 November 2022. RESULTS: We assessed 2613 studies and included 18 from 10 countries, covering 1-125 C-sections: the United States, the United Kingdom, Australia, India, Italy, China, France, The Netherlands, New Zealand and Taiwan. The papers were published from 2014 to 2023, and the majority were randomised controlled trials and observational studies. Different platforms, equipment and staff positions in relation to the operating table were described. Options for resuscitation and stabilisation included different bedding and trolley approaches, and maintaining aseptic conditions was mainly addressed by the neonatal team scrubbing in. Hypothermia was prevented by using warm surfaces, polythene bags and radiant heaters. Equipment was kept easily accessible by mounting it on a trolley or a separate mobile pole. CONCLUSION: We could not reach definitive conclusions on the optimal method for performing ICR/S during a C-section, due to study variations. However, a number of equipment and management options appeared to be feasible approaches.

Human saliva, plasma and breast milk exosomes contain RNA: uptake by macrophages.

BACKGROUND: Exosomes are 30-100 nm membrane vesicles of endocytic origin produced by numerous cells. They can mediate diverse biological functions, including antigen presentation. Exosomes have recently been shown to contain functional RNA, which can be delivered to other cells. Exosomes may thus mediate biological functions either by surface-to-surface interactions with cells, or by the delivery of functional RNA to cells. Our aim was therefore to determine the presence of RNA in exosomes from human saliva, plasma and breast milk and whether these exosomes can be taken up by macrophages. METHOD: Exosomes were purified from human saliva, plasma and breast milk using ultracentrifugation and filtration steps. Exosomes were detected by electron microscopy and examined by flow cytometry. Flow cytometry was performed by capturing the exosomes on anti-MHC class II coated beads, and further stain with anti-CD9, anti-CD63 or anti-CD81. Breast milk exosomes were further analysed for the presence of Hsc70, CD81 and calnexin by Western blot. Total RNA was detected with a Bioanalyzer and mRNA was identified by the synthesis of cDNA using an oligo (dT) primer and analysed with a Bioanalyzer. The uptake of PKH67-labelled saliva and breast milk exosomes by macrophages was examined by measuring fluorescence using flow cytometry and fluorescence microscopy. RESULTS: RNA was detected in exosomes from all three body fluids. A portion of the detected RNA in plasma exosomes was characterised as mRNA. Our result extends the characterisation of exosomes in healthy humans and confirms the presence of RNA in human saliva and plasma exosomes and reports for the first time the presence of RNA in breast milk exosomes. Our results also show that the saliva and breast milk exosomes can be taken up by human macrophages. CONCLUSIONS: Exosomes in saliva, plasma and breast milk all contain RNA, confirming previous findings that exosomes from several sources contain RNA. Furthermore, exosomes are readily taken up by macrophages, supporting the notion that exosomal RNA can be shuttled between cells.