Nutrient sensing in the nucleus of the solitary tract mediates non-aversive suppression of feeding via inhibition of AgRP neurons.

UNLABELLED: The nucleus of the solitary tract (NTS) is emerging as a major site of action for the appetite-suppressive effects of leading pharmacotherapies currently investigated to treat obesity. However, our understanding of how NTS neurons regulate appetite remains incomplete. OBJECTIVES: In this study, we used NTS nutrient sensing as an entry point to characterize stimulus-defined neuronal ensembles engaged by the NTS to produce physiological satiety. METHODS: We combined histological analysis, neuroanatomical assessment using inducible viral tracing tools, and functional tests to characterize hindbrain-forebrain circuits engaged by NTS leucine sensing to suppress hunger. RESULTS: We found that NTS detection of leucine engages NTS prolactin-releasing peptide (PrRP) neurons to inhibit AgRP neurons via a population of leptin receptor-expressing neurons in the dorsomedial hypothalamus. This circuit is necessary for the anorectic response to NTS leucine, the appetite-suppressive effect of high-protein diets, and the long-term control of energy balance. CONCLUSIONS: These results extend the integrative capability of AgRP neurons to include brainstem nutrient sensing inputs

Increased Production of Abdominal Donor Site Fluid Following Microsurgical Breast Reconstruction With Superficial Inferior Epigastric Artery Versus Deep Inferior Epigastric Artery Perforator Flaps

Introduction and aims: Donor site seroma following abdominal flap harvest for breast reconstruction is common in both deep inferior epigastric artery perforator (DIEP) and superficial inferior epigastric artery (SIEA) flaps. We tested the hypothesis that there is increased donor site fluid following SIEA dissection compared to DIEP.Materials and methods: Of 60 SIEA breast reconstructions performed by one surgeon in 50 patients (2004-2019), complete data were available for 31 patients. Eighteen unilateral SIEAs were matched with 18 unilateral DIEPs. Thirteen bilateral flap harvests involving an SIEA were matched with 13 bilateral DIEP controls. Their cumulative abdominal drain outputs, times to drain removal, hospital stay, and number and volume of seroma aspirations were compared.Results: Patients who underwent an SIEA flap harvest had significantly increased drain output compared to only a DIEP flap harvest (SIEA=1,078 mL, DIEP=500 mL, pConclusion: This study demonstrated that SIEA harvest is a significant predictor of increased abdominal drain output postoperatively. This accounted for longer periods before drain removal and more patients discharged with an abdominal drain in situ and should be an important consideration for reconstructive surgeons. There was no demonstrable difference in the number or volume of seroma aspirations after drain removal for either group.</p

Increased Production of Abdominal Donor Site Fluid Following Microsurgical Breast Reconstruction With Superficial Inferior Epigastric Artery Versus Deep Inferior Epigastric Artery Perforator Flaps

Donor site seroma following abdominal flap harvest for breast reconstruction is common in both deep inferior epigastric artery perforator (DIEP) and superficial inferior epigastric artery (SIEA) flaps. We tested the hypothesis that there is increased donor site fluid following SIEA dissection compared to DIEP