Association Between Social Determinants of Health and Retinopathy of Prematurity Outcomes.

Importance: Previous studies suggest that race or ethnicity may be associated with risk for developing retinopathy of prematurity (ROP). Little is known about how socioeconomic factors mediate the relationship between race or ethnicity and ROP outcomes. Objective: To evaluate how socioeconomic factors, in the context of race and ethnicity, are associated with ROP outcomes. Design, Setting, and Participants: This retrospective cohort study used US Census Bureau income data and electronic medical records from neonatal intensive care units at 4 hospitals, UCLA Mattel Children's Hospital, UCLA Santa Monica Hospital, Cedars-Sinai Medical Center, and Harbor-UCLA Medical Center. Eligible participants included neonates born at a gestational age (GA) of 30 weeks or less, birth weight less than 1500 g, or a GA at birth greater than 30 weeks but with an unstable clinical course. Participants were screened for ROP between January 1, 2010, and December 31, 2020. Exposures: Race and ethnicity data, GA, demographic and clinical information, proxy household income, and health insurance status were collected as risk factors. Main Outcomes and Measures: Diagnosis and severity of ROP were the main study outcomes. Severity was determined according to a classification system developed by the Early Treatment for Retinopathy of Prematurity Cooperative Group. Results: In a crude model, Hispanic neonates were more likely to be diagnosed with ROP (OR, 1.70; 95% CI, 1.20-2.42) and had more severe ROP (OR, 2.24; 95% CI, 1.21-4.15) compared with non-Hispanic White neonates; these associations were no longer found when adjusting for GA and socioeconomic factors (OR, 1.12; 95% CI, 0.68-1.82, and OR, 1.67; 95% CI, 0.80-3.52, for ROP diagnosis and severity, respectively). In a fully adjusted model, lower GA was the primary predictor of ROP incidence (OR, 0.52; 95% CI, 0.48-0.57; P < .001), and higher median household income was associated with higher GA (OR, 0.26; 95% CI, 0.09-0.43; P = .002). Conclusions and Relevance: In this cohort study, GA was the primary driver of disparities in ROP outcomes in a heterogeneous population of neonates in Los Angeles, California. When examined in the context of socioeconomic factors, GA did not differ between racial and ethnic groups. Studies of disparities associated with race and ethnicity should consider these constructs in conjunction with other sociodemographic factors and social determinants of health.

Targeting hepatocyte carbohydrate transport to mimic fasting and calorie restriction.

The pervasion of three daily meals and snacks is a relatively new introduction to our shared experience and is coincident with an epidemic rise in obesity and cardiometabolic disorders of overnutrition. The past two decades have yielded convincing evidence regarding the adaptive, protective effects of calorie restriction (CR) and intermittent fasting (IF) against cardiometabolic, neurodegenerative, proteostatic, and inflammatory diseases. Yet, durable adherence to intensive lifestyle changes is rarely attainable. New evidence now demonstrates that restricting carbohydrate entry into the hepatocyte by itself mimics several key signaling responses and physiological outcomes of IF and CR. This discovery raises the intriguing proposition that targeting hepatocyte carbohydrate transport to mimic fasting and caloric restriction can abate cardiometabolic and perhaps other fasting-treatable diseases. Here, we review the metabolic and signaling fates of a hepatocyte carbohydrate, identify evidence to target the key mediators within these pathways, and provide rationale and data to highlight carbohydrate transport as a broad, proximal intervention to block the deleterious sequelae of hepatic glucose and fructose metabolism.

Tidal Flow Perfusion for the Artificial Placenta: A Paradigm Shift.

The modalities of vascular access for the extracorporeal artificial placenta (AP) have undergone many iterations over the past decade. We hypothesized that single lumen cannulation (SLC) of the jugular vein using tidal flow extracorporeal life (ECLS) support is a feasible alternative to venovenous (VV) umbilical-jugular cannulation and double lumen cannulation (DLC) and can maintain fetal circulation, stable hemodynamics, and adequate gas exchange for 24 hours. After in vitro evaluation of the tidal flow system, six preterm lambs at estimated gestational age 118-124 days (term 145 days) were delivered and underwent VV-ECLS. Three were supported using DLC and three with SLC utilizing tidal flow AP support. Hemodynamics, circuit flow, and gas exchange were monitored. Target fetal parameters were as follows: mean arterial pressure 40-60 mmHg, heart rate 140-240 beats per minute (bpm), SatO2% 60-80%, PaO2 25-50 mmHg, PaCO2 30-55 mmHg, oxygen delivery >5 ml O2/dl/kg/min, and circuit flow 100 ± 25 ml/kg/min. All animals survived 24 hours and maintained fetal circulation with stable hemodynamics and adequate gas exchange. Parameters of the tidal flow group were comparable with those of DLC. Single lumen jugular cannulation using tidal flow is a promising vascular access strategy for AP support. Successful miniaturization holds great potential for clinical translation to support extremely premature infants.

The use of low-cost Android tablets to train community health workers in Mukono, Uganda, in the recognition, treatment and prevention of pneumonia in children under five: a pilot randomised controlled trial.

BACKGROUND: Since 2012, The World Health Organization and UNICEF have advocated for community health workers (CHWs) to be trained in Integrated Community Case Management (iCCM) of common childhood illnesses, such as pneumonia. Despite the effectiveness of iCCM, CHWs face many barriers to accessing training. This pilot study compares traditional training with using locally made videos loaded onto low-cost Android tablets to train CHWs on the pneumonia component of iCCM. METHODS: We conducted a pilot randomised controlled trial with CHWs in the Mukono District of Uganda. The unit of randomisation was the sub-county level, and the unit of analysis was at the level of the individual CHW. Eligible CHWs had completed basic iCCM training but had not received any refresher training on the pneumonia component of iCCM in the preceding 2 years. CHWs in the control group received training in the recognition, treatment, and prevention of pneumonia as it is currently delivered, through a 1-day, in-person workshop. CHWs allocated to the intervention group received training via locally made educational videos hosted on low-cost Android tablets. The primary outcome was change in knowledge acquisition, assessed through a multiple choice questionnaire before and after training, and a post-training clinical assessment. The secondary outcome was a qualitative evaluation of CHW experiences of using the tablet platform. RESULTS: In the study, 129 CHWs were enrolled, 66 and 63 in the control and intervention groups respectively. CHWs in both groups demonstrated an improvement in multiple choice question test scores before and after training; however, there was no statistically significant difference in the improvement between groups (t = 1.15, p = 0.254). There was a statistically significant positive correlation (Pearson's r = 0.26, p = 0.03) linking years of education to improvement in test scores in the control group, which was not present in the intervention group. The majority of CHWs expressed satisfaction with the use of tablets as a training tool; however, some reported technical issues (n = 9). CONCLUSION: Tablet-based training is comparable to traditional training in terms of knowledge acquisition. It also proved to be feasible and a satisfactory means of delivering training to CHWs. Further research is required to understand the impacts of scaling such an intervention. TRIAL REGISTRATION: Registered on 23/11/2016 at clinicaltrials.gov ( NCT02971449 ).

N-cadherin restrains PTH activation of Lrp6/ß-catenin signaling and osteoanabolic action.

Interaction between parathyroid hormone/parathyroid hormone-related peptide receptor 1 (PTHR1) and low-density lipoprotein receptor-related protein 6 (Lrp6) is important for parathyroid hormone (PTH) signaling and anabolic action. Because N-cadherin has been shown to negatively regulate canonical Wnt/ß-catenin signaling, we asked whether N-cadherin alters PTH signaling and stimulation of bone formation. Ablation of the N-cadherin gene (Cdh2) in primary osteogenic lineage cells resulted in increased Lrp6/PTHR1 interaction in response to PTH1-34 , associated with enhanced PTH-induced PKA signaling and PKA-dependent ß-catenin C-terminus phosphorylation, which promotes ß-catenin transcriptional activity. ß-catenin C-terminus phosphorylation was abolished by Lrp6 knockdown. Accordingly, PTH1-34 stimulation of Tcf/Lef target genes, Lef1 and Axin2, was also significantly enhanced in Cdh2-deficient cells. This enhanced responsiveness to PTH extends to the osteo-anabolic effect of PTH, as mice with a conditional Cdh2 deletion in Osx+ cells treated with intermittent doses of PTH1-34 exhibited significantly larger gains in trabecular bone mass relative to control mice, the result of accentuated osteoblast activity. Therefore, N-cadherin modulates Lrp6/PTHR1 interaction, restraining the intensity of PTH-induced ß-catenin signaling, and ultimately influencing bone formation in response to intermittent PTH administration.

NLRP3 mediates osteolysis through inflammation-dependent and -independent mechanisms.

Activating-mutations in NOD-like receptor (NLR) family, pyrin domain-containing 3 (NLRP3) cause neonatal-onset multisystem inflammatory disease. However, the ontogeny of skeletal anomalies in this disorder is poorly understood. Mice globally expressing the D301N mutation in Nlrp3 (D303N in human) model the human phenotype, including systemic inflammation and skeletal deformities. To gain insights into the skeletal manifestations, we generated mice in which the expression of D301N Nlrp3 (Nlrp3( D301N)) is restricted to myeloid cells. These mice exhibit systemic inflammation and severe osteopenia (∼ 60% lower bone mass) similar to mice globally expressing the knock-in mutation, consistent with the paradigm of innate immune-driven cryopyrinopathies. Because systemic inflammation may indirectly affect bone homeostasis, we engineered mice in which Nlrp3( D301N) is expressed specifically in osteoclasts, the cells that resorb bone. These mice also develop ∼ 50% lower bone mass due to increased osteolysis, but there is no systemic inflammation and no change in osteoclast number. Mechanistically, aside from its role in IL-1ß maturation, Nlrp3( D301N) expression enhances osteoclast bone resorbing ability through reorganization of actin cytoskeleton while promoting the degradation of poly(ADP-ribose) polymerase 1, an inhibitor of osteoclastogenesis. Thus, NLRP3 inflammasome activation is not restricted to the production of proinflammatory mediators but also leads to cytokine-autonomous responses.

Postnatal ablation of osteoblast Smad4 enhances proliferative responses to canonical Wnt signaling through interactions with ß-catenin.

Canonical Wnt (cWnt) signaling through ß-catenin regulates osteoblast proliferation and differentiation to enhance bone formation. We previously reported that osteogenic action of ß-catenin is dependent on BMP signaling. Here, we further examined interactions between cWnt and BMP in bone. In osteoprogenitors stimulated with BMP2, ß-catenin localizes to the nucleus, physically interacts with Smad4, and is recruited to DNA-binding transcription complexes containing Smad4, R-Smad1/5 and TCF4. Furthermore, Tcf/Lef-dependent transcription, Ccnd1 expression and proliferation all increase when Smad4, 1 or 5 levels are low, whereas TCF/Lef activities decrease when Smad4 expression is high. The ability of Smad4 to antagonize transcription of Ccnd1 is dependent on DNA-binding activity but Smad4-dependent transcription is not required. In mice, conditional deletion of Smad4 in osterix(+) cells increases mitosis of cells on trabecular bone surfaces as well as in primary osteoblast cultures from adult bone marrow and neonatal calvaria. By contrast, ablation of Smad4 delays differentiation and matrix mineralization by primary osteoblasts in response to Wnt3a, indicating that loss of Smad4 perturbs the balance between proliferation and differentiation in osteoprogenitors. We propose that Smad4 and Tcf/Lef transcription complexes compete for ß-catenin, thus restraining cWnt-dependent proliferative signals while favoring the matrix synthesizing activity of osteoblasts.