We previously reported low sensitivity of the hepatitis B virus (HBV) ribonuclease H (RNaseH) enzyme to inhibition by N-hydroxyisoquinolinedione (HID) compounds. Subsequently, our biochemical RNaseH assay was found to have a high false negative rate for predicting HBV replication inhibition, leading to underestimation of the number of HIDs that inhibit HBV replication. Here, 39 HID compounds and structurally related polyoxygenated heterocycles (POH), N-hydroxypyridinediones (HPD), and flutimides were screened for inhibition of HBV replication in vitro. Inhibiting the HBV RNaseH preferentially blocks synthesis of the positive-polarity DNA strand and causes accumulation of RNA:DNA heteroduplexes. Eleven HIDs and one HPD preferentially inhibited HBV positive-polarity DNA strand accumulation. EC50s ranged from 0.69 μM to 19 μM with therapeutic indices from 2.4 – 71. Neither the HIDs nor the HPD had an effect on the ability of the polymerase to elongate DNA strands in capsids. HBV RNaseH inhibition by the HIDs was confirmed with an improved RNaseH assay and by detecting accumulation RNA:DNA heteroduplexes in HBV capsids from cells treated with a representative HID. Therefore, the HID scaffold is more promising for anti-HBV drug discovery than we originally reported, and the HPD scaffold may hold potential for antiviral development. The preliminary structure-activity relationship will guide optimization of the HID/HPDs as HBV inhibitors.

Background Maternal nutrient restriction (MNR) is a widespread cause of fetal growth restriction (FGR), an independent predictor of heart disease and cardiovascular mortality. Our objective was to examine the developmental and long-term impact of MNR-induced FGR on cardiac structure in a model that closely mimics human development. Methods A reduction in total caloric intake spanning pre-gestation through to lactation in guinea pig sows was used to induce FGR. Proliferation, differentiation, and apoptosis of cardiomyocytes were assessed in late-gestation fetal, neonatal, and adult guinea pig hearts. Proteomic analysis and pathway enrichment were performed on fetal hearts. Results Cardiomyocyte proliferation and number of mononucleated cells was enhanced in the MNR-FGR fetal and neonatal heart, suggesting a delay in cardiomyocyte differentiation. In fetal hearts of MNR-FGR animals, apoptosis was markedly elevated and the total number of cardiomyocytes reduced, the latter remaining so throughout neonatal and into adult life. A reduction in total cardiomyocyte number in adult MNR-FGR hearts was accompanied by exaggerated hypertrophy and a disorganized architecture. Pathway analysis identified genes related to cell proliferation, differentiation, and survival. Conclusions FGR influences cardiomyocyte development during critical windows of development, leading to a permanent deficiency in cardiomyocyte number and compensatory hypertrophy in a rodent model that recapitulates human development.

Background:The objective of this study was to determine whether human milk supplemented with a novel human milk-based human milk fortifier (Novel HMF), compared with a bovine milk-based HMF (Bovine HMF), supports preterm infant growth through 36 weeks' postmenstrual age (PMA).Methods: This single-center, prospective trial compared growth and nutrition outcomes of preterm infants provided a human milk-based diet (mother's own milk or donor milk) supplemented with a Novel HMF with historic controls provided Bovine HMF. Preterm infants with an estimated gestational age (EGA) between 23 and 33 weeks' PMA and birth weight between 750 and 1800 g were eligible for study inclusion. Weight, length, and head circumference (HC) were monitored weekly. The occurrence of late-onset sepsis, nil per os (NPO) days, necrotizing enterocolitis, metabolic acidosis, and serious adverse events were monitored.Results: Birth weight, length, HC, and EGA were similar between the Novel HMF (n = 37) and Bovine HMF (n = 49) groups. The days to regain birth weight was shorter in the Novel HMF group (9.4 ± 4.0 vs 11.4 ± 4.8, P = .0343), with similar weight gain (g/day) from birth to 36 weeks' PMA. Adjusted weight growth velocity (g/kg/day) was significantly higher in the Novel HMF group at 14 and 21 days but similar at 36 weeks' PMA. The Novel HMF group experienced fewer NPO days with a similar total number of feeding days.Conclusions: A novel, multinutrient, human milk-based HMF is well tolerated and meets the nutrition needs of preterm infants.