High Fat Feeding Induces Hepatic Fatty Acid Elongation in Mice

BACKGROUND:High-fat diets promote hepatic lipid accumulation. Paradoxically, these diets also induce lipogenic gene expression in rodent liver. Whether high expression of these genes actually results in an increased flux through the de novo lipogenic pathway in vivo has not been demonstrated. METHODOLOGY/PRINCIPAL FINDINGS:To interrogate this apparent paradox, we have quantified de novo lipogenesis in C57Bl/6J mice fed either chow, a high-fat or a n-3 polyunsaturated fatty acid (PUFA)-enriched high-fat diet. A novel approach based on mass isotopomer distribution analysis (MIDA) following 1-(13)C acetate infusion was applied to simultaneously determine de novo lipogenesis, fatty acid elongation as well as cholesterol synthesis. Furthermore, we measured very low density lipoprotein-triglyceride (VLDL-TG) production rates. High-fat feeding promoted hepatic lipid accumulation and induced the expression of lipogenic and cholesterogenic genes compared to chow-fed mice: induction of gene expression was found to translate into increased oleate synthesis. Interestingly, this higher lipogenic flux (+74 microg/g/h for oleic acid) in mice fed the high-fat diet was mainly due to an increased hepatic elongation of unlabeled palmitate (+66 microg/g/h) rather than to elongation of de novo synthesized palmitate. In addition, fractional cholesterol synthesis was increased, i.e. 5.8+/-0.4% vs. 8.1+/-0.6% for control and high fat-fed animals, respectively. Hepatic VLDL-TG production was not affected by high-fat feeding. Partial replacement of saturated fat by fish oil completely reversed the lipogenic effects of high-fat feeding: hepatic lipogenic and cholesterogenic gene expression levels as well as fatty acid and cholesterol synthesis rates were normalized. CONCLUSIONS/SIGNIFICANCE:High-fat feeding induces hepatic fatty acid synthesis in mice, by chain elongation and subsequent desaturation rather than de novo synthesis, while VLDL-TG output remains unaffected. Suppression of lipogenic fluxes by fish oil prevents from high fat diet-induced hepatic steatosis in mice

Physical connections and cooperation in swarm robotics

We describe a new multi-robot system, named SWARM-BOTS, that exploits physical inter-connections to solve tasks that are impossible for a single robot. This is for instance the case of passing large gaps or high steps in all-terrain conditions. In order to achieve this type of autonomous collective operations, the design of the type of connection, as well as its sensors and actuators, plays a key role. This paper presents the choices made in the SWARM-BOTS project and the know-how collected until now. The requirements for autonomous operation and mobility of each robots have led to the development of a connectivity very different those found in selfrecon gurable robots. Some of the solutions employed for this problem are inspired upon physical connectivity of social insects. We also illustrate with two experiments how sensors and actuators allow autonomous operation in connection, release as well as passive and active exploitation of inter-robot degrees of freedom (DOF)

From Cryptic Toward Canonical Pre-mRNA Splicing in Pompe Disease: A Pipeline for the Development of Antisense Oligonucleotides

While 9% of human pathogenic variants have an established effect on pre-mRNA splicing, it is suspected that an additional 20% of otherwise classified variants also affect splicing. Aberrant splicing includes disruption of splice sites or regulatory elements, or creation or strengthening of cryptic splice sites. For the majority of variants, it is poorly understood to what extent and how these may affect splicing. We have identified cryptic splicing in an unbiased manner. Three types of cryptic splicing were analyzed in the context of pathogenic variants in the acid α-glucosidase gene causing Pompe disease. These involved newly formed deep intronic or exonic cryptic splice sites, and a natural cryptic splice that was utilized due to weakening of a canonical splice site. Antisense oligonucleotides that targeted the identified cryptic splice sites repressed cryptic splicing at the expense of canonical splicing in all three cases, as shown by reverse-transcriptase-quantitative polymerase chain reaction analysis and by enhancement of acid α-glucosidase enzymatic activity. This argues for a competition model for available splice sites, including intact or weakened canonical sites and natural or newly formed cryptic sites. The pipeline described here can detect cryptic splicing and correct canonical splicing using antisense oligonucleotides to restore the gene defect

3D fusion of intravascular ultrasound and coronary computed tomography for in-vivo wall shear stress analysis: A feasibility study

Wall shear stress, the force per area acting on the lumen wall due to the blood flow, is an important biomechanical parameter in the localization and progression of atherosclerosis. To calculate shear stress and relate it to atherosclerosis, a 3D description of the lumen and vessel wall is required. We present a framework to obtain the 3D reconstruction of human coronary arteries by the fusion of intravascular ultrasound (IVUS) and coronary computed tomography angiography (CT). We imaged 23 patients with IVUS and CT. The images from both modalities were registered for 35 arteries, using bifurcations as landmarks. The IVUS images together with IVUS derived lumen and wall contours were positioned on the 3D centerline, which was derived from CT. The resulting 3D lumen and wall contours were transformed to a surface for calculation of shear stress and plaque thickness. We applied variations in selection of landmarks and investigated whether these variations influenced the relation between shear stress and plaque thickness. Fusion was successfully achieved in 31 of the 35 arteries. The average length of the fused segments was 36.4 ± 15.7 mm. The length in IVUS and CT of the fused parts correlated excellently (R2= 0.98). Both for a mildly diseased and a very diseased coronary artery, shear stress was calculated and related to plaque thickness. Variations in the selection of the landmarks for these two arteries did not affect the relationship between shear stress and plaque thickness. This new framework can therefore successfully be applied for shear stress analysis in human coronary arteries

Randomised controlled trial of first-line tyrosine-kinase inhibitor (TKI) versus intercalated TKI with chemotherapy for EGFR-mutated nonsmall cell lung cancer

Introduction Previous studies have shown interference between epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors and chemotherapy in the cell cycle, thus reducing efficacy. In this randomised controlled trial we investigated whether intercalated erlotinib with chemotherapy was superior compared to erlotinib alone in untreated advanced EGFR-mutated nonsmall cell lung cancer (NSCLC). Materials and methods Treatment-naïve patients with an activating EGFR mutation, ECOG performance score of 0–3 and adequate organ function were randomly assigned 1:1 to either four cycles of cisplatin-pemetrexed with intercalated erlotinib (day 2–16 out of 21 days per cycle) followed by pemetrexed and erlotinib maintenance (CPE) or erlotinib monotherapy. The primary end-point was progression-free survival (PFS). Secondary end-points were overall survival, objective response rate (ORR) and toxicity. Results Between April 2014 and September 2016, 22 patients were randomised equally into both arms; the study was stopped due to slow accrual. Median follow-up was 64 months. Median PFS was 13.7 months (95% CI 5.2–18.8) for CPE and 10.3 months (95% CI 7.1–15.5; hazard ratio (HR) 0.62, 95% CI 0.25–1.57) for erlotinib monotherapy; when compensating for number of days receiving erlotinib, PFS of the CPE arm was superior (HR 0.24, 95% CI 0.07–0.83; p=0.02). ORR was 64% for CPE versus 55% for erlotinib monotherapy. Median overall survival was 31.7 months (95% CI 21.8–61.9 months) for CPE compared to 17.2 months (95% CI 11.5–45.5 months) for erlotinib monotherapy (HR 0.58, 95% CI 0.22–1.41 months). Patients treated with CPE had higher rates of treatment-related fatigue, anorexia, weight loss and renal toxicity. Conclusion Intercalating erlotinib with cisplatin-pemetrexed provides a longer PFS compared to erlotinib alone in EGFR-mutated NSCLC at the expense of more toxicity

Segmental and total uniparental isodisomy (UPiD) as a disease mechanism in autosomal recessive lysosomal disorders : evidence from SNP arrays

Analyses in our diagnostic DNA laboratory include genes involved in autosomal recessive (AR) lysosomal storage disorders such as glycogenosis type II (Pompe disease) and mucopolysaccharidosis type I (MPSI, Hurler disease). We encountered 4 cases with apparent homozygosity for a disease-causing sequence variant that could be traced to one parent only. In addition, in a young child with cardiomyopathy, in the absence of other symptoms, a diagnosis of Pompe disease was considered. Remarkably, he presented with different enzymatic and genotypic features between leukocytes and skin fibroblasts. All cases were examined with microsatellite markers and SNP genotyping arrays. We identified one case of total uniparental disomy (UPD) of chromosome 17 leading to Pompe disease and three cases of segmental uniparental isodisomy (UPiD) causing Hurler-(4p) or Pompe disease (17q). One Pompe patient with unusual combinations of features was shown to have a mosaic segmental UPiD of chromosome 17q. The chromosome 17 UPD cases amount to 11% of our diagnostic cohort of homozygous Pompe patients (plus one case of pseudoheterozygosity) where segregation analysis was possible. We conclude that inclusion of parental DNA is mandatory for reliable DNA diagnostics. Mild or unusual phenotypes of AR diseases should alert physicians to the possibility of mosaic segmental UPiD. SNP genotyping arrays are used in diagnostic workup of patients with developmental delay. Our results show that even small Regions of Homozygosity that include telomeric areas are worth reporting, regardless of the imprinting status of the chromosome, as they might indicate segmental UPiD.Peer reviewe

Segmental and total uniparental isodisomy (UPiD) as a disease mechanism in autosomal recessive lysosomal

Analyses in our diagnostic DNA laboratory include genes involved in autosomal recessive (AR) lysosomal storage disorders such as glycogenosis type II (Pompe disease) and mucopolysaccharidosis type I (MPSI, Hurler disease). We encountered 4 cases with apparent homozygosity for a disease-causing sequence variant that could be traced to one parent only. In addition, in a young child with cardiomyopathy, in the absence of other symptoms, a diagnosis of Pompe disease was considered. Remarkably, he presented with different enzymatic and genotypic features between leukocytes and skin fibroblasts. All cases were examined with microsatellite markers and SNP genotyping arrays. We identified one case of total uniparental disomy (UPD) of chromosome 17 leading to Pompe disease and three cases of segmental uniparental isodisomy (UPiD) causing Hurler-(4p) or Pompe disease (17q). One Pompe patient with unusual combinations of features was shown to have a mosaic segmental UPiD of chromosome 17q. The chromosome 17 UPD cases amount to 11% of our diagnostic cohort of homozygous Pompe patients (plus one case of pseudoheterozygosity) where segregation analysis was possible. We conclude that inclusion of parental DNA is mandatory for reliable DNA diagnostics. Mild or unusual phenotypes of AR diseases should alert physicians to the possibility of mosaic segmental UPiD. SNP genotyping arrays are used in diagnostic workup of patients with developmental delay. Our results show that even small Regions of Homozygosity that include telomeric areas are worth reporting, regardless of the imprinting status of the chromosome, as they might indicate segmental UPiD

Randomised phase 3 study of adjuvant chemotherapy with or without nadroparin in patients with completely resected non-small-cell lung cancer:the NVALT-8 study

Background: Retrospective studies suggest that low molecular weight heparin may delay the development of metastasis in patients with resected NSCLC. Methods: Multicentre phase 3 study with patients with completely resected NSCLC who were randomised after surgery to receive chemotherapy with or without nadroparin. The main exclusion criteria were R1/2 and wedge/segmental resection. FDG-PET was required. The primary endpoint was recurrence-free survival (RFS). Results: Among 235 registered patients, 202 were randomised (nadroparin: n = 100; control n = 102). Slow accrual enabled a decrease in the number of patients needed from 600 to 202, providing 80% power to compare RFS with 94 events (α = 0.05; 2-sided). There were no differences in bleeding events between the two groups. The median RFS was 65.2 months (95% CI, 36—NA) in the nadroparin arm and 37.7 months (95% CI, 22.7—NA) in the control arm (HR 0.77 (95% CI, 0.53–1.13, P = 0.19). FDG-PET SUVmax ≥10 predicted a greater likelihood of recurrence in the first year (HR 0.48, 95% CI 0.22–0.9, P = 0.05). Conclusions: Adjuvant nadroparin did not improve RFS in patients with resected NSCLC. In this study, a high SUVmax predicted a greater likelihood of recurrence in the first year. Clinical trial registration: Netherlands Trial registry: NTR1250/1217