Genetic ablation or chemical inhibition of phosphatidylcholine transfer protein attenuates diet?induced hepatic glucose production†‡

 Phosphatidylcholine transfer protein (PC?TP, synonym StARD2) is a highly specific intracellular lipid binding protein that is enriched in liver. Coding region polymorphisms in both humans and mice appear to confer protection against measures of insulin resistance. The current study was designed to test the hypotheses that Pctp?/? mice are protected against diet?induced increases in hepatic glucose production and that small molecule inhibition of PC?TP recapitulates this phenotype. Pctp?/? and wildtype mice were subjected to high?fat feeding and rates of hepatic glucose production and glucose clearance were quantified by hyperinsulinemic euglycemic clamp studies and pyruvate tolerance tests. These studies revealed that high?fat diet?induced increases in hepatic glucose production were markedly attenuated in Pctp?/? mice. Small molecule inhibitors of PC?TP were synthesized and their potencies, as well as mechanism of inhibition, were characterized in vitro. An optimized inhibitor was administered to high?fat?fed mice and used to explore effects on insulin signaling in cell culture systems. Small molecule inhibitors bound PC?TP, displaced phosphatidylcholines from the lipid binding site, and increased the thermal stability of the protein. Administration of the optimized inhibitor to wildtype mice attenuated hepatic glucose production associated with high?fat feeding, but had no activity in Pctp?/? mice. Indicative of a mechanism for reducing glucose intolerance that is distinct from commonly utilized insulin?sensitizing agents, the inhibitor promoted insulin?independent phosphorylation of key insulin signaling molecules. Conclusion: These findings suggest PC?TP inhibition as a novel therapeutic strategy in the management of hepatic insulin resistance

Heterogeneous Liver on Research Ultrasound Identifies Children with Cystic Fibrosis at High Risk of Advanced Liver Disease: Interim Results of a Prospective Observational Case-Controlled Study

Objective: To assess if a heterogeneous pattern on research liver ultrasound examination can identify children at risk for advanced cystic fibrosis (CF) liver disease. Study design: Planned 4-year interim analysis of a 9-year multicenter, case-controlled cohort study (Prospective Study of Ultrasound to Predict Hepatic Cirrhosis in CF). Children with pancreatic insufficient CF aged 3-12 years without known cirrhosis, Burkholderia species infection, or short bowel syndrome underwent a screening research ultrasound examination. Participants with a heterogeneous liver ultrasound pattern were matched (by age, Pseudomonas infection status, and center) 1:2 with participants with a normal pattern. Clinical status and laboratory data were obtained annually and research ultrasound examinations biannually. The primary end point was the development of a nodular research ultrasound pattern, a surrogate for advanced CF liver disease. Results: There were 722 participants who underwent screening research ultrasound examination, of which 65 were heterogeneous liver ultrasound pattern and 592 normal liver ultrasound pattern. The final cohort included 55 participants with a heterogeneous liver ultrasound pattern and 116 participants with a normal liver ultrasound pattern. All participants with at least 1 follow-up research ultrasound were included. There were no differences in age or sex between groups at entry. Alanine aminotransferase (42 ± 22 U/L vs 32 ± 19 U/L; P = .0033), gamma glutamyl transpeptidase (36 ± 34 U/L vs 15 ± 8 U/L; P < .001), and aspartate aminotransferase to platelet ratio index (0.7 ± 0.5 vs 0.4 ± 0.2; P < .0001) were higher in participants with a heterogeneous liver ultrasound pattern compared with participants with a normal liver ultrasound pattern. Participants with a heterogeneous liver ultrasound pattern had a 9.1-fold increased incidence (95% CI, 2.7-30.8; P = .0004) of nodular pattern vs a normal liver ultrasound pattern (23% in heterogeneous liver ultrasound pattern vs 2.6% in normal liver ultrasound pattern). Conclusions: Research liver ultrasound examinations can identify children with CF at increased risk for developing advanced CF liver disease

Non-invasive bladder function measures in healthy, asymptomatic female children and adolescents: A systematic review and meta-analysis

BackgroundLower urinary tract symptoms (LUTS) are common in children and adolescents. Non-invasive tests evaluating bladder function are generally preferred over invasive tests, yet few studies have explored the range of normative values for these tests in healthy, asymptomatic children.ObjectiveTo define normative reference ranges for non-invasive tests of bladder function in healthy, asymptomatic girls and adolescents.Study designA comprehensive search strategy was performed in seven electronic databases through October 2019. English-language studies reporting data on voiding frequency, voided and postvoid residual volumes (PVR) and uroflowmetry results in healthy, asymptomatic girls (mean age&nbsp;≥&nbsp;5 years) were included. Two independent reviewers performed study review, data extraction, and quality assessment. Overall mean estimates and 95% confidence intervals for each bladder function parameter were calculated using random effects models, and 95% normative reference values were estimated.ResultsTen studies met eligibility criteria for the meta-analysis (n&nbsp;=&nbsp;2143 girls, age range: 3-18). Mean estimates of maximum voided volume and PVR were 233.4&nbsp;ml (95% CI 204.3-262.6; n&nbsp;=&nbsp;1 study) and 8.6&nbsp;ml (95% CI 4.8-12.4; n&nbsp;=&nbsp;2 studies) respectively. Pooled mean estimates for uroflowmetry parameters were: 21.5&nbsp;ml/s (95% CI 20.5-2.5) for maximum flow rate (n&nbsp;=&nbsp;6 studies), 12.5&nbsp;ml/s (95% CI 11.2-13.8) for mean flow rate (n&nbsp;=&nbsp;6 studies), 6.8&nbsp;s (95% CI 4.4-9.3) for time to maximum flow (n&nbsp;=&nbsp;3 studies), 15.7&nbsp;s (95% CI 13.0-18.5) for flow time (n&nbsp;=&nbsp;3 studies), and 198.7&nbsp;ml (95% CI 154.2-234.2) for voided volume (n&nbsp;=&nbsp;9 studies). No studies reported estimates of voiding frequency. Between-study heterogeneity was high (89.0-99.6%).ConclusionsAlthough we were able to calculate pooled mean estimates for several parameters, the small number of included studies and the wide age ranges of participants preclude generalization of reference values to all healthy girls. Further research is needed to determine normative reference values within specific age groups