The discovery and enhanced properties of trichain lipids in lipopolyplex gene delivery systems

The formation of a novel trichain (TC) lipid was discovered when a cationic lipid possessing a terminal hydroxyl group and the helper lipid dioleoyl l-α-phosphatidylethanolamine (DOPE) were formulated as vesicles and stored. Importantly, the transfection efficacies of lipopolyplexes comprised of the TC lipid, a targeting peptide and DNA (LPDs) were found to be higher than when the corresponding dichain (DC) lipid was used. To explore this interesting discovery and determine if this concept can be more generally applied to improve gene delivery efficiencies, the design and synthesis of a series of novel TC cationic lipids and the corresponding DC lipids was undertaken. Transfection efficacies of the LPDs were found to be higher when using the TC lipids compared to the DC analogues, so experiments were carried out to investigate the reasons for this enhancement. Sizing experiments and transmission electron microscopy indicated that there were no major differences in the size and shape of the LPDs prepared using the TC and DC lipids, while circular dichroism spectroscopy showed that the presence of the third acyl chain did not influence the conformation of the DNA within the LPD. In contrast, small angle neutron scattering studies showed a considerable re-arrangement of lipid conformation upon formulation as LPDs, particularly of the TC lipids, while gel electrophoresis studies revealed that the use of a TC lipid in the LPD formulation resulted in enhanced DNA protection properties. Thus, the major enhancement in transfection performance of these novel TC lipids can be attributed to their ability to protect and subsequently release DNA. Importantly, the TC lipids described here highlight a valuable structural template for the generation of gene delivery vectors, based on the use of lipids with three hydrophobic chains

ATP synthase deficiency due to TMEM70 mutation leads to ultrastructural mitochondrial degeneration and is amenable to treatment.

TMEM70 is involved in the biogenesis of mitochondrial ATP synthase and mutations in the TMEM70 gene impair oxidative phosphorylation. Herein, we report on pathology and treatment of ATP synthase deficiency in four siblings. A consanguineous family of Roma (Gipsy) ethnic origin gave birth to 6 children of which 4 were affected presenting with dysmorphic features, failure to thrive, cardiomyopathy, metabolic crises, and 3-methylglutaconic aciduria as clinical symptoms. Genetic testing revealed a homozygous mutation (c.317-2A>G) in the TMEM70 gene. While light microscopy was unremarkable, ultrastructural investigation of muscle tissue revealed accumulation of swollen degenerated mitochondria with lipid crystalloid inclusions, cristae aggregation, and exocytosis of mitochondrial material. Biochemical analysis of mitochondrial complexes showed an almost complete ATP synthase deficiency. Despite harbouring the same mutation, the clinical outcome in the four siblings was different. Two children died within 60 h after birth; the other two had recurrent life-threatening metabolic crises but were successfully managed with supplementation of anaplerotic amino acids, lipids, and symptomatic treatment during metabolic crisis. In summary, TMEM70 mutations can cause distinct ultrastructural mitochondrial degeneration and almost complete deficiency of ATP synthase but are still amenable to treatment

A novel pathogenic variant in MYO18B associating early-onset muscular hypotonia, and characteristic dysmorphic features, delineation of the phenotypic spectrum of MYO18B-related conditions.

Homozygous loss-of-function variants in MYO18B have been associated with congenital myopathy, facial dysmorphism and Klippel-Feil anomaly. So far, only four patients have been reported. Comprehensive description of new cases that help to highlight recurrent features and to further delineate the phenotypic spectrum are still missing. We present the fifth case of MYO18B-associated disease in a newborn male patient. Trio exome sequencing identified the previously unreported homozygous nonsense variant c.6433C > T, p.(Arg2145*) in MYO18B (NM_032608.5). While most phenotypic features of our patient align with previously reported cases, we describe the prenatal features for the first time. Taking the phenotypic description of our patient into account, we propose that the core phenotype comprises a severe congenital myopathy with feeding difficulties in infancy and characteristic dysmorphic features

Adjoint-based model predictive control of wind farms: Beyond the quasi steady-state power maximization

In this paper, we extend our closed-loop optimal control framework for wind farms to minimize wake-induced power losses. We develop an adjoint-based model predictive controller which employs a medium-fidelity 2D dynamic wind farm model. The wind turbine axial induction factors are considered here as the control inputs to influence the overall performance by taking wake interactions of the wind turbines into account. A constrained optimization problem is formulated to maximize the total power production of a given wind farm. An adjoint approach as an efficient tool is utilized to compute the gradient for such a large-scale system. The computed gradient is then modified to deal with the defined final set and practical constraints on the wind turbine control inputs. The performance of the wind farm controller is examined for a more realistic test case, a layout of a 2 x 3 wind farm with dynamical changes in wind direction. The effectiveness of the proposed approach is studied through simulations.Team Jan-Willem van Wingerde

Adjoint-based model predictive control of wind farms: Beyond the quasi steady-state power maximization

In this paper, we extend our closed-loop optimal control framework for wind farms to minimize wake-induced power losses. We develop an adjoint-based model predictive controller which employs a medium-fidelity 2D dynamic wind farm model. The wind turbine axial induction factors are considered here as the control inputs to influence the overall performance by taking wake interactions of the wind turbines into account. A constrained optimization problem is formulated to maximize the total power production of a given wind farm. An adjoint approach as an efficient tool is utilized to compute the gradient for such a large-scale system. The computed gradient is then modified to deal with the defined final set and practical constraints on the wind turbine control inputs. The performance of the wind farm controller is examined for a more realistic test case, a layout of a 2 x 3 wind farm with dynamical changes in wind direction. The effectiveness of the proposed approach is studied through simulations.</p

T-cell homeostasis in pediatric multiple sclerosis: old cells in young patients

OBJECTIVE: To assess pediatric patients with multiple sclerosis (MS) for early signs of homeostatic and functional abnormalities in conventional (Tcon) and regulatory T cells (Treg). METHODS: We studied the composition of the peripheral T-cell compartment and Treg function in a cross-sectional study with 30 pediatric MS (pMS) patients by multicolor flow cytometry and proliferation assays. Data were compared to those obtained from adult patients (n = 26) and age-matched control donors (n = 67). RESULTS: Proportions of naive T cells were 10%-20% higher in children than in adults, reflecting the age-related decline. pMS patients, however, had clearly lower numbers of naive T cells, among them recent thymic emigrants (RTE), whereas percentages of memory T cells were increased. In the Treg compartment, reduced RTE numbers coincided with markedly dampened suppressive capacities of total Treg. These homeostatic changes in circulating T cells precisely paralleled the pattern seen in adult MS. As in adults, treatment with immunomodulatory drugs attenuated these alterations. CONCLUSION: The homeostatic changes detected in the T-cell compartment in pMS are similar to those in adult-onset disease. With ratios between naive and memory T-cell subsets matching those of 20- to 30-years-older controls, signs of early thymic involution are already found in pMS, suggesting that an intrinsic compromise in thymic-dependent T-cell neogenesis might contribute to MS pathogenesis