Natural History of NAFLD Diagnosed in Childhood: A Single-Center Study

Little is known regarding the subsequent course of non-alcoholic fatty liver disease (NAFLD) diagnosed in childhood. The objectives of this single-center study were to gather data on long-term health outcomes and to assess the feasibility of contacting former pediatric patients. In a large pediatric medical center, electronic records were searched to initially identify 162 former patients who had a liver biopsy between 2000 and 2010. Of these, 44 subjects met the criteria for age at follow-up (≥18 year) and biopsy-proven NAFLD, and were recruited via postal and electronic mail. Participants were invited to complete a brief telephone survey on current health status. Supplemental data was also obtained from pediatric medical charts of all subjects. At NAFLD diagnosis, 18% of subjects had diabetes, 91% were obese, 61% had NASH, and 56% had fibrosis on biopsy. At follow-up, 10 subjects (23%) responded to the survey. Based on the survey and chart review, after a mean follow-up of 4.5 years, 5 additional subjects developed diabetes for a period prevalence of 30%, and most subjects (78%) remained obese at last follow-up. Additional prospective studies are needed to fully describe the longitudinal risks associated with pediatric NAFLD, and will require multi-dimensional strategies to successfully recruit former patients

Cytoplasmic acidification and the benzoate transcriptome in Bacillus subtilis.

BACKGROUND:Bacillus subtilis encounters a wide range of environmental pH. The bacteria maintain cytoplasmic pH within a narrow range. Response to acid stress is a poorly understood function of external pH and of permeant acids that conduct protons into the cytoplasm. METHODS AND PRINCIPAL FINDINGS:Cytoplasmic acidification and the benzoate transcriptome were observed in Bacillus subtilis. Cytoplasmic pH was measured with 4-s time resolution using GFPmut3b fluorimetry. Rapid external acidification (pH 7.5 to 6.0) acidified the B. subtilis cytoplasm, followed by partial recovery. Benzoate addition up to 60 mM at external pH 7 depressed cytoplasmic pH but left a transmembrane Delta pH permitting growth; this robust adaptation to benzoate exceeds that seen in E. coli. Cytoplasmic pH was depressed by 0.3 units during growth with 30 mM benzoate. The transcriptome of benzoate-adapted cells was determined by comparing 4,095 gene expression indices following growth at pH 7, +/- 30 mM benzoate. 164 ORFs showed > or = 2-fold up-regulation by benzoate (30 mM benzoate/0 mM), and 102 ORFs showed > or = 2-fold down-regulation. 42% of benzoate-dependent genes are regulated up or down, respectively, at pH 6 versus pH 7; they are candidates for cytoplasmic pH response. Acid-stress genes up-regulated by benzoate included drug resistance genes (yhbI, yhcA, yuxJ, ywoGH); an oligopeptide transporter (opp); glycine catabolism (gcvPA-PB); acetate degradation (acsA); dehydrogenases (ald, fdhD, serA, yrhEFG, yjgCD); the TCA cycle (citZ, icd, mdh, sucD); and oxidative stress (OYE-family yqjM, ohrB). Base-stress genes down-regulated by benzoate included malate metabolism (maeN), sporulation control (spo0M, spo0E), and the SigW alkali shock regulon. Cytoplasmic pH could mediate alkali-shock induction of SigW. CONCLUSIONS:B. subtilis maintains partial pH homeostasis during growth, and withstands high concentrations of permeant acid stress, higher than for gram-negative neutralophile E. coli. The benzoate adaptation transcriptome substantially overlaps that of external acid, contributing to a cytoplasmic pH transcriptome

A randomized, controlled, crossover pilot study of losartan for pediatric nonalcoholic fatty liver disease

Abstract Background Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease in children, and currently, there are no FDA-approved therapies. Plasminogen activator inhibitor-1 (PAI-1) is elevated in children with NAFLD and associated with increased disease severity. Losartan potassium (losartan) is an angiotensin II receptor blocker (ARB) that reduces PAI-1 production and improves insulin sensitivity that has been proposed as a treatment for pediatric NAFLD but has not previously been tested. Methods This was an 8-week randomized, double-blind, placebo-controlled, phase 2a, crossover study (with a 6-week washout between conditions) for safety and preliminary efficacy of losartan 50 mg a day taken orally in 12 normotensive children with biopsy proven nonalcoholic steatohepatitis (NASH). Results Twelve children enrolled in the study, and nine completed all visits. No changes in blood pressure or serious adverse events occurred during the study. Trends in improvement in alanine aminotransferase (ALT), aspartate aminotransferase (AST), and homeostatic model assessment insulin resistance (HOMA-IR) were seen with losartan treatment compared to the placebo time-period. More participants decreased ALT on losartan as compared to placebo (89% [8 out 9] vs. 56% [5 out of 9], respectively). Conclusions This data provides preliminary evidence that losartan treatment is safe over 8 weeks in children with NAFLD and supports consideration of larger studies to test its efficacy. Trial registration URL and trial identification number: https://clinicaltrials.gov/show/NCT01913470, NCT01913470. Date registered: August 1, 2013

Whole Genome Assembly of the Gulf Coast Tick \u3ci\u3eAmblyomma maculatum\u3c/i\u3e

Course-based Undergraduate Research Experiences (CUREs) involve classes of students addressing real-world research questions without pre-defined outcomes. BIOL380/381, Research in Pathogen Biology (RiP-Bio), was designed as an advanced CURE for 300-level Biology students at ODU. In this cycle of RiP-Bio, we are sequencing and assembling the whole genome of Amblyomma maculatum, the Gulf Coast tick. The current assembly of the genome is incomplete, as we have only short Illumina reads that do not fully assemble. We are using published mRNA sequences from the A. maculatum transcriptome to scaffold the incomplete assembly, and create primers for gap closure of important genes. Assembled genes will be deposited for use by others in Genbank

Effect of a Low Free Sugar Diet vs Usual Diet on Nonalcoholic Fatty Liver Disease in Adolescent Boys: A Randomized Clinical Trial.

ImportancePediatric guidelines for the management of nonalcoholic fatty liver disease (NAFLD) recommend a healthy diet as treatment. Reduction of sugary foods and beverages is a plausible but unproven treatment.ObjectiveTo determine the effects of a diet low in free sugars (those sugars added to foods and beverages and occurring naturally in fruit juices) in adolescent boys with NAFLD.Design, setting, and participantsAn open-label, 8-week randomized clinical trial of adolescent boys aged 11 to 16 years with histologically diagnosed NAFLD and evidence of active disease (hepatic steatosis >10% and alanine aminotransferase level ≥45 U/L) randomized 1:1 to an intervention diet group or usual diet group at 2 US academic clinical research centers from August 2015 to July 2017; final date of follow-up was September 2017.InterventionsThe intervention diet consisted of individualized menu planning and provision of study meals for the entire household to restrict free sugar intake to less than 3% of daily calories for 8 weeks. Twice-weekly telephone calls assessed diet adherence. Usual diet participants consumed their regular diet.Main outcomes and measuresThe primary outcome was change in hepatic steatosis estimated by magnetic resonance imaging proton density fat fraction measurement between baseline and 8 weeks. The minimal clinically important difference was assumed to be 4%. There were 12 secondary outcomes, including change in alanine aminotransferase level and diet adherence.ResultsForty adolescent boys were randomly assigned to either the intervention diet group or the usual diet group (20 per group; mean [SD] age, 13.0 [1.9] years; most were Hispanic [95%]) and all completed the trial. The mean decrease in hepatic steatosis from baseline to week 8 was significantly greater for the intervention diet group (25% to 17%) vs the usual diet group (21% to 20%) and the adjusted week 8 mean difference was -6.23% (95% CI, -9.45% to -3.02%; P < .001). Of the 12 prespecified secondary outcomes, 7 were null and 5 were statistically significant including alanine aminotransferase level and diet adherence. The geometric mean decrease in alanine aminotransferase level from baseline to 8 weeks was significantly greater for the intervention diet group (103 U/L to 61 U/L) vs the usual diet group (82 U/L to 75 U/L) and the adjusted ratio of the geometric means at week 8 was 0.65 U/L (95% CI, 0.53 to 0.81 U/L; P < .001). Adherence to the diet was high in the intervention diet group (18 of 20 reported intake of <3% of calories from free sugar during the intervention). There were no adverse events related to participation in the study.Conclusions and relevanceIn this study of adolescent boys with NAFLD, 8 weeks of provision of a diet low in free sugar content compared with usual diet resulted in significant improvement in hepatic steatosis. However, these findings should be considered preliminary and further research is required to assess long-term and clinical outcomes.Trial registrationClinicalTrials.gov Identifier: NCT02513121

Dietary sugar restriction reduces hepatic de novo lipogenesis in adolescent boys with fatty liver disease

BACKGROUNDHepatic de novo lipogenesis (DNL) is elevated in nonalcoholic fatty liver disease (NAFLD). Improvements in hepatic fat by dietary sugar reduction may be mediated by reduced DNL, but data are limited, especially in children. We examined the effects of 8 weeks of dietary sugar restriction on hepatic DNL in adolescents with NAFLD and correlations between DNL and other metabolic outcomes.METHODSAdolescent boys with NAFLD (n = 29) participated in an 8-week, randomized controlled trial comparing a diet low in free sugars versus their usual diet. Hepatic DNL was measured as percentage contribution to plasma triglyceride palmitate using a 7-day metabolic labeling protocol with heavy water. Hepatic fat was measured by magnetic resonance imaging-proton density fat fraction.RESULTSHepatic DNL was significantly decreased in the treatment group (from 34.6% to 24.1%) versus the control group (33.9% to 34.6%) (adjusted week 8 mean difference: -10.6% [95% CI: -19.1%, -2.0%]), which was paralleled by greater decreases in hepatic fat (25.5% to 17.9% vs. 19.5% to 18.8%) and fasting insulin (44.3 to 34.7 vs. 35.5 to 37.0 μIU/mL). Percentage change in DNL during the intervention correlated significantly with changes in free-sugar intake (r = 0.48, P = 0.011), insulin (r = 0.40, P = 0.047), and alanine aminotransferase (ALT) (r = 0.39, P = 0.049), but not hepatic fat (r = 0.13, P = 0.532).CONCLUSIONOur results suggest that dietary sugar restriction reduces hepatic DNL and fasting insulin, in addition to reductions in hepatic fat and ALT, among adolescents with NAFLD. These results are consistent with the hypothesis that hepatic DNL is a critical metabolic abnormality linking dietary sugar and NAFLD.TRIAL REGISTRYClinicalTrials.gov NCT02513121.FUNDINGThe Nutrition Science Initiative (made possible by gifts from the Laura and John Arnold Foundation, Ambrose Monell Foundation, and individual donors), the UCSD Altman Clinical and Translational Research Institute, the NIH, Children's Healthcare of Atlanta and Emory University's Children's Clinical and Translational Discovery Core, Children's Healthcare of Atlanta and Emory University Pediatric Biostatistical Core, the Georgia Clinical and Translational Science Alliance, and the NIH National Institute of Diabetes, Digestive, and Kidney Disease