854 research outputs found

    An international registry for neurodegeneration with brain iron accumulation

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    We report the development of an international registry for Neurodegeneration with Brain Iron Accumulation (NBIA), in the context of TIRCON (Treat Iron-Related Childhood-Onset Neurodegeneration), an EU-FP7-funded project. This registry aims to combine scattered resources, integrate clinical and scientific knowledge, and generate a rich source for future research studies. This paper describes the content, architecture and future utility of the registry with the intent to capture as many NBIA patients as possible and to offer comprehensive information to the international scientific community

    Proliferation of genetically modified human cells on electrospun nanofiber scaffolds.

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    Gene editing is a process by which single base mutations can be corrected, in the context of the chromosome, using single-stranded oligodeoxynucleotides (ssODNs). The survival and proliferation of the corrected cells bearing modified genes, however, are impeded by a phenomenon known as reduced proliferation phenotype (RPP); this is a barrier to practical implementation. To overcome the RPP problem, we utilized nanofiber scaffolds as templates on which modified cells were allowed to recover, grow, and expand after gene editing. Here, we present evidence that some HCT116-19, bearing an integrated, mutated enhanced green fluorescent protein (eGFP) gene and corrected by gene editing, proliferate on polylysine or fibronectin-coated polycaprolactone (PCL) nanofiber scaffolds. In contrast, no cells from the same reaction protocol plated on both regular dish surfaces and polylysine (or fibronectin)-coated dish surfaces proliferate. Therefore, growing genetically modified (edited) cells on electrospun nanofiber scaffolds promotes the reversal of the RPP and increases the potential of gene editing as an ex vivo gene therapy application.Molecular Therapy - Nucleic Acids (2012) 1, e59; doi:10.1038/mtna.2012.51; published online 4 December 2012

    Liquid Metal-Elastomer Soft Composites with Independently Controllable and Highly Tunable Droplet Size and Volume Loading

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    Soft composites are critical for soft and flexible materials in energy harvesting, actuators, and multifunctional devices. One emerging approach to create multifunctional composites is through the incorporation of liquid metal (LM) droplets such as eutectic gallium indium (EGaIn) in highly deformable elastomers. The microstructure of such systems is critical to their performance, however, current materials lack control of particle size at diverse volume loadings. Here, we present a fabrication approach to create liquid metal-elastomer composites with independently controllable and highly tunable droplet size (100 nm ≦ D ≦ 80 ΞΌm) and volume loading (0 ≦ Ο† ≦ 80%). This is achieved through a combination of shear mixing and sonication of concentrated LM/elastomer emulsions to control droplet size and subsequent dilution and homogenization to tune LM volume loading. These materials are characterized utilizing dielectric spectroscopy supported by analytical modeling which shows a high relative permittivity of 60 (16x the unfilled elastomer) in a composite with Ο† = 80%, a low tan Ξ΄ of 0.02, and a significant dependence on Ο† and minor dependence on droplet size. Temperature response and stability are determined using dielectric spectroscopy through temperature and frequency sweeps and with DSC. These results demonstrate a wide temperature stability of the liquid metal phase (crystallizing \u3c -85 Β°C for D \u3c 20 ΞΌm). Additionally, all composites are electrically insulating across a wide frequency (0.1 Hz - 10 MHz) and temperature (-70Β°C to 100Β°C) range even up to Ο† = 80%. We highlight the benefit of LM microstructure control by creating all soft matter stretchable capacitive sensors with tunable sensitivity. These sensors are further integrated into a wearable sensing glove where we identify different objects during grasping motions. This work enables programmable LM composites for soft robotics and stretchable electronics where flexibility and tunable functional response are critical

    A Nuclear Export Signal in KHNYN Required for Its Antiviral Activity Evolved as ZAP Emerged in Tetrapods

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    The zinc finger antiviral protein (ZAP) inhibits viral replication by directly binding CpG dinucleotides in cytoplasmic viral RNA to inhibit protein synthesis and target the RNA for degradation. ZAP evolved in tetrapods and there are clear orthologs in reptiles, birds, and mammals. When ZAP emerged, other proteins may have evolved to become cofactors for its antiviral activity. KHNYN is a putative endoribonuclease that is required for ZAP to restrict retroviruses. To determine its evolutionary path after ZAP emerged, we compared KHNYN orthologs in mammals and reptiles to those in fish, which do not encode ZAP. This identified residues in KHNYN that are highly conserved in species that encode ZAP, including several in the CUBAN domain. The CUBAN domain interacts with NEDD8 and Cullin-RING E3 ubiquitin ligases. Deletion of the CUBAN domain decreased KHNYN antiviral activity, increased protein expression and increased nuclear localization. However, mutation of residues required for the CUBAN domain-NEDD8 interaction increased KHNYN abundance but did not affect its antiviral activity or cytoplasmic localization, indicating that Cullin-mediated degradation may control its homeostasis and regulation of protein turnover is separable from its antiviral activity. By contrast, the C-terminal residues in the CUBAN domain form a CRM1-dependent nuclear export signal (NES) that is required for its antiviral activity. Deletion or mutation of the NES increased KHNYN nuclear localization and decreased its interaction with ZAP. The final 2 positions of this NES are not present in fish KHNYN orthologs and we hypothesize their evolution allowed KHNYN to act as a ZAP cofactor. IMPORTANCE The interferon system is part of the innate immune response that inhibits viruses and other pathogens. This system emerged approximately 500 million years ago in early vertebrates. Since then, some genes have evolved to become antiviral interferon-stimulated genes (ISGs) while others evolved so their encoded protein could interact with proteins encoded by ISGs and contribute to their activity. However, this remains poorly characterized. ZAP is an ISG that arose during tetrapod evolution and inhibits viral replication. Because KHNYN interacts with ZAP and is required for its antiviral activity against retroviruses, we conducted an evolutionary analysis to determine how specific amino acids in KHNYN evolved after ZAP emerged. This identified a nuclear export signal that evolved in tetrapods and is required for KHNYN to traffic in the cell and interact with ZAP. Overall, specific residues in KHNYN evolved to allow it to act as a cofactor for ZAP antiviral activity

    Identification of Autophagy as a Functional Target Suitable for the Pharmacological Treatment of Mitochondrial Membrane Protein-Associated Neurodegeneration (MPAN) In Vitro

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    Mitochondrial membrane protein-associated neurodegeneration (MPAN) is a relentlessly progressive neurodegenerative disorder caused by mutations in the C19orf12 gene. C19orf12 has been implicated in playing a role in lipid metabolism, mitochondrial function, and autophagy, however, the precise functions remain unknown. To identify new robust cellular targets for small compound treatments, we evaluated reported mitochondrial function alterations, cellular signaling, and autophagy in a large cohort of MPAN patients and control fibroblasts. We found no consistent alteration of mitochondrial functions or cellular signaling messengers in MPAN fibroblasts. In contrast, we found that autophagy initiation is consistently impaired in MPAN fibroblasts and show that C19orf12 expression correlates with the amount of LC3 puncta, an autophagy marker. Finally, we screened 14 different autophagy modulators to test which can restore this autophagy defect. Amongst these compounds, carbamazepine, ABT-737, LY294002, oridonin, and paroxetine could restore LC3 puncta in the MPAN fibroblasts, identifying them as novel potential therapeutic compounds to treat MPAN. In summary, our study confirms a role for C19orf12 in autophagy, proposes LC3 puncta as a functionally robust and consistent readout for testing compounds, and pinpoints potential therapeutic compounds for MPAN

    Brain Iron and Metabolic Abnormalities in C19orf12 Mutation Carriers: A 7.0 Tesla MRI Study in Mitochondrial Membrane Protein–Associated Neurodegeneration

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    Background Mitochondrial membrane protein‐associated neurodegeneration is an autosomal‐recessive disorder caused by C19orf12 mutations and characterized by iron deposits in the basal ganglia. Objectives The aim of this study was to quantify iron concentrations in deep gray matter structures using quantitative susceptibility mapping MRI and to characterize metabolic abnormalities in the pyramidal pathway using 1H MR spectroscopy in clinically manifesting membrane protein‐associated neurodegeneration patients and asymptomatic C19orf12 gene mutation heterozygous carriers. Methods We present data of 4 clinically affected membrane protein‐associated neurodegeneration patients (mean age: 21.0 ± 2.9 years) and 9 heterozygous gene mutation carriers (mean age: 50.4 ± 9.8 years), compared to age‐matched healthy controls. MRI assessments were performed on a 7.0 Tesla whole‐body system, consisting of whole‐brain gradient‐echo scans and short echo time, single‐volume MR spectroscopy in the white matter of the precentral/postcentral gyrus. Quantitative susceptibility mapping, a surrogate marker for iron concentration, was performed using a state‐of‐the‐art multiscale dipole inversion approach with focus on the globus pallidus, thalamus, putamen, caudate nucleus, and SN. Results and Conclusion In membrane protein‐associated neurodegeneration patients, magnetic susceptibilities were 2 to 3 times higher in the globus pallidus (P = 0.02) and SN (P = 0.02) compared to controls. In addition, significantly higher magnetic susceptibility was observed in the caudate nucleus (P = 0.02). Non‐manifesting heterozygous mutation carriers exhibited significantly increased magnetic susceptibility (relative to controls) in the putamen (P = 0.003) and caudate nucleus (P = 0.001), which may be an endophenotypic marker of genetic heterozygosity. MR spectroscopy revealed significantly increased levels of glutamate, taurine, and the combined concentration of glutamate and glutamine in membrane protein‐associated neurodegeneration, which may be a correlate of corticospinal pathway dysfunction frequently observed in membrane protein‐associated neurodegeneration patients

    First-In-Human Study in Cancer Patients Establishing the Feasibility of Oxygen Measurements in Tumors Using Electron Paramagnetic Resonance With the OxyChip

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    Objective: The overall objective of this clinical study was to validate an implantable oxygen sensor, called the β€˜OxyChip’, as a clinically feasible technology that would allow individualized tumor-oxygen assessments in cancer patients prior to and during hypoxia-modification interventions such as hyperoxygen breathing. Methods: Patients with any solid tumor at ≀3-cm depth from the skin-surface scheduled to undergo surgical resection (with or without neoadjuvant therapy) were considered eligible for the study. The OxyChip was implanted in the tumor and subsequently removed during standard-of-care surgery. Partial pressure of oxygen (pO2) at the implant location was assessed using electron paramagnetic resonance (EPR) oximetry. Results: Twenty-three cancer patients underwent OxyChip implantation in their tumors. Six patients received neoadjuvant therapy while the OxyChip was implanted. Median implant duration was 30 days (range 4–128 days). Forty-five successful oxygen measurements were made in 15 patients. Baseline pO2 values were variable with overall median 15.7 mmHg (range 0.6–73.1 mmHg); 33% of the values were below 10 mmHg. After hyperoxygenation, the overall median pO2 was 31.8 mmHg (range 1.5–144.6 mmHg). In 83% of the measurements, there was a statistically significant (p ≀ 0.05) response to hyperoxygenation. Conclusions: Measurement of baseline pO2 and response to hyperoxygenation using EPR oximetry with the OxyChip is clinically feasible in a variety of tumor types. Tumor oxygen at baseline differed significantly among patients. Although most tumors responded to a hyperoxygenation intervention, some were non-responders. These data demonstrated the need for individualized assessment of tumor oxygenation in the context of planned hyperoxygenation interventions to optimize clinical outcomes

    Improvement of microstructure and mechanical properties of high dense SiC ceramics manufactured by high-speed hot pressing

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    Non-oxide ceramics possess high physical-mechanical properties, corrosion and radiation resistance, which can be used as a protective materials for radioactive wastes disposal. The aim of the present study was the manufacturing of high density SiC ceramics with advanced physical and mechanical parameters. The high performance on the properties of produced ceramics was determined by the dense and monolithic structure. The densified silicon carbide samples possessed good mechanical strength, with a high Vickers micro hardness up to 28.5 GPa.БСзкиснСві ΠΊΠ΅Ρ€Π°ΠΌΡ–Ρ‡Π½Ρ– ΠΌΠ°Ρ‚Π΅Ρ€Ρ–Π°Π»ΠΈ Π΄Π΅ΠΌΠΎΠ½ΡΡ‚Ρ€ΡƒΡŽΡ‚ΡŒ високі Ρ„Ρ–Π·ΠΈΠΊΠΎ-ΠΌΠ΅Ρ…Π°Π½Ρ–Ρ‡Π½Ρ– властивості, ΠΊΠΎΡ€ΠΎΠ·Ρ–ΠΉΠ½Ρƒ Ρ‚Π° Ρ€Π°Π΄Ρ–Π°Ρ†Ρ–ΠΉΠ½Ρƒ ΡΡ‚Ρ–ΠΉΠΊΡ–ΡΡ‚ΡŒ, Ρ‰ΠΎ Ρ€ΠΎΠ±Π»ΡΡ‚ΡŒ Ρ—Ρ… пСрспСктивними ΠΊΠ°Π½Π΄ΠΈΠ΄Π°Ρ‚Π°ΠΌΠΈ для використання Π² якості Π±Π°Ρ€'Ρ”Ρ€Π½ΠΈΡ… ΠΌΠ°Ρ‚Π΅Ρ€Ρ–Π°Π»Ρ–Π² для захоронСння Ρ€Π°Π΄Ρ–ΠΎΠ°ΠΊΡ‚ΠΈΠ²Π½ΠΈΡ… Π²Ρ–Π΄Ρ…ΠΎΠ΄Ρ–Π². ΠœΠ΅Ρ‚ΠΎΡŽ Ρ†Ρ–Ρ”Ρ— Ρ€ΠΎΠ±ΠΎΡ‚ΠΈ Π±ΡƒΠ»ΠΎ отримання Π²ΠΈΡΠΎΠΊΠΎΡ‰Ρ–Π»ΡŒΠ½ΠΎΡ— SiC-ΠΊΠ΅Ρ€Π°ΠΌΡ–ΠΊΠΈ Π· вдосконалСними Ρ„Ρ–Π·ΠΈΡ‡Π½ΠΈΠΌΠΈ Ρ– ΠΌΠ΅Ρ…Π°Π½Ρ–Ρ‡Π½ΠΈΠΌΠΈ властивостями. Високі ΠΏΠ°Ρ€Π°ΠΌΠ΅Ρ‚Ρ€ΠΈ ΠΎΡ‚Ρ€ΠΈΠΌΠ°Π½ΠΎΡ— ΠΊΠ΅Ρ€Π°ΠΌΡ–ΠΊΠΈ Π²ΠΈΠ·Π½Π°Ρ‡Π°ΡŽΡ‚ΡŒΡΡ формуванням Π²ΠΈΡΠΎΠΊΠΎΡ‰Ρ–Π»ΡŒΠ½ΠΎΡ— Ρ– ΠΌΠΎΠ½ΠΎΠ»Ρ–Ρ‚Π½ΠΎΡ— структури. ΠšΠ΅Ρ€Π°ΠΌΡ–ΠΊΠ° ΠΊΠ°Ρ€Π±Ρ–Π΄Ρƒ ΠΊΡ€Π΅ΠΌΠ½Ρ–ΡŽ ΠΌΠ°Ρ” ΠΏΠΎΠ»Ρ–ΠΏΡˆΠ΅Π½Ρƒ ΠΌΠ΅Ρ…Π°Π½Ρ–Ρ‡Π½Ρƒ ΠΌΡ–Ρ†Π½Ρ–ΡΡ‚ΡŒ Ρ– високу Ρ‚Π²Π΅Ρ€Π΄Ρ–ΡΡ‚ΡŒ ΠΏΠΎ ВіккСрсу порядка 28,5 Π“ΠŸa.БСскислородныС кСрамичСскиС ΠΌΠ°Ρ‚Π΅Ρ€ΠΈΠ°Π»Ρ‹ Π΄Π΅ΠΌΠΎΠ½ΡΡ‚Ρ€ΠΈΡ€ΡƒΡŽΡ‚ высокиС Ρ„ΠΈΠ·ΠΈΠΊΠΎ-мСханичСскиС свойства, ΠΊΠΎΡ€Ρ€ΠΎΠ·ΠΈΠΎΠ½Π½ΡƒΡŽ ΠΈ Ρ€Π°Π΄ΠΈΠ°Ρ†ΠΈΠΎΠ½Π½ΡƒΡŽ ΡΡ‚ΠΎΠΉΠΊΠΎΡΡ‚ΡŒ, Π΄Π΅Π»Π°ΡŽΡ‰ΠΈΠ΅ ΠΈΡ… пСрспСктивными ΠΊΠ°Π½Π΄ΠΈΠ΄Π°Ρ‚Π°ΠΌΠΈ для использования Π² качСствС Π±Π°Ρ€ΡŒΠ΅Ρ€Π½Ρ‹Ρ… ΠΌΠ°Ρ‚Π΅Ρ€ΠΈΠ°Π»ΠΎΠ² для захоронСния Ρ€Π°Π΄ΠΈΠΎΠ°ΠΊΡ‚ΠΈΠ²Π½Ρ‹Ρ… ΠΎΡ‚Ρ…ΠΎΠ΄ΠΎΠ². ЦСлью настоящСй Ρ€Π°Π±ΠΎΡ‚Ρ‹ Π±Ρ‹Π»ΠΎ ΠΏΠΎΠ»ΡƒΡ‡Π΅Π½ΠΈΠ΅ высокоплотной SiC-ΠΊΠ΅Ρ€Π°ΠΌΠΈΠΊΠΈ с ΡƒΡΠΎΠ²Π΅Ρ€ΡˆΠ΅Π½ΡΡ‚Π²ΠΎΠ²Π°Π½Π½Ρ‹ΠΌΠΈ физичСскими ΠΈ мСханичСскими свойствами. ВысокиС ΠΏΠ°Ρ€Π°ΠΌΠ΅Ρ‚Ρ€Ρ‹ ΠΏΠΎΠ»ΡƒΡ‡Π΅Π½Π½ΠΎΠΉ ΠΊΠ΅Ρ€Π°ΠΌΠΈΠΊΠΈ ΠΎΠΏΡ€Π΅Π΄Π΅Π»ΡΡŽΡ‚ΡΡ Ρ„ΠΎΡ€ΠΌΠΈΡ€ΠΎΠ²Π°Π½ΠΈΠ΅ΠΌ высокоплотной ΠΈ ΠΌΠΎΠ½ΠΎΠ»ΠΈΡ‚Π½ΠΎΠΉ структуры. ΠšΠ΅Ρ€Π°ΠΌΠΈΠΊΠ° ΠΊΠ°Ρ€Π±ΠΈΠ΄Π° крСмния ΠΎΠ±Π»Π°Π΄Π°Π΅Ρ‚ ΡƒΠ»ΡƒΡ‡ΡˆΠ΅Π½Π½ΠΎΠΉ мСханичСской ΠΏΡ€ΠΎΡ‡Π½ΠΎΡΡ‚ΡŒΡŽ ΠΈ высокой Ρ‚Π²Π΅Ρ€Π΄ΠΎΡΡ‚ΡŒΡŽ ΠΏΠΎ ВиккСрсу порядка 28,5 Π“ΠŸa
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