894 research outputs found
An international registry for neurodegeneration with brain iron accumulation
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.
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
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 β¦ D β¦ 80 ΞΌm) and volume loading (0 β¦ Ο β¦ 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
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
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 ProteinβAssociated Neurodegeneration
Background
Mitochondrial membrane proteinβassociated neurodegeneration is an autosomalβrecessive 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 proteinβassociated neurodegeneration patients and asymptomatic C19orf12 gene mutation heterozygous carriers.
Methods
We present data of 4 clinically affected membrane proteinβassociated neurodegeneration patients (mean age: 21.0βΒ±β2.9βyears) and 9 heterozygous gene mutation carriers (mean age: 50.4βΒ±β9.8βyears), compared to ageβmatched healthy controls. MRI assessments were performed on a 7.0 Tesla wholeβbody system, consisting of wholeβbrain gradientβecho scans and short echo time, singleβvolume MR spectroscopy in the white matter of the precentral/postcentral gyrus. Quantitative susceptibility mapping, a surrogate marker for iron concentration, was performed using a stateβofβtheβart multiscale dipole inversion approach with focus on the globus pallidus, thalamus, putamen, caudate nucleus, and SN.
Results and Conclusion
In membrane proteinβassociated neurodegeneration patients, magnetic susceptibilities were 2 to 3 times higher in the globus pallidus (Pβ=β0.02) and SN (Pβ=β0.02) compared to controls. In addition, significantly higher magnetic susceptibility was observed in the caudate nucleus (Pβ=β0.02). Nonβmanifesting heterozygous mutation carriers exhibited significantly increased magnetic susceptibility (relative to controls) in the putamen (Pβ=β0.003) and caudate nucleus (Pβ=β0.001), 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 proteinβassociated neurodegeneration, which may be a correlate of corticospinal pathway dysfunction frequently observed in membrane proteinβassociated neurodegeneration patients
First-In-Human Study in Cancer Patients Establishing the Feasibility of Oxygen Measurements in Tumors Using Electron Paramagnetic Resonance With the OxyChip
Objective: The overall objective of this clinical study was to validate an implantable oxygen sensor, called the βOxyChipβ, 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 β€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 4β128 days). Forty-five successful oxygen measurements were made in 15 patients. Baseline pO2 values were variable with overall median 15.7 mmHg (range 0.6β73.1 mmHg); 33% of the values were below 10 mmHg. After hyperoxygenation, the overall median pO2 was 31.8 mmHg (range 1.5β144.6 mmHg). In 83% of the measurements, there was a statistically significant (p β€ 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
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.ΠΠ΅Π·ΠΊΠΈΡΠ½Π΅Π²Ρ ΠΊΠ΅ΡΠ°ΠΌΡΡΠ½Ρ ΠΌΠ°ΡΠ΅ΡΡΠ°Π»ΠΈ Π΄Π΅ΠΌΠΎΠ½ΡΡΡΡΡΡΡ Π²ΠΈΡΠΎΠΊΡ ΡΡΠ·ΠΈΠΊΠΎ-ΠΌΠ΅Ρ
Π°Π½ΡΡΠ½Ρ Π²Π»Π°ΡΡΠΈΠ²ΠΎΡΡΡ, ΠΊΠΎΡΠΎΠ·ΡΠΉΠ½Ρ ΡΠ° ΡΠ°Π΄ΡΠ°ΡΡΠΉΠ½Ρ ΡΡΡΠΉΠΊΡΡΡΡ, ΡΠΎ ΡΠΎΠ±Π»ΡΡΡ ΡΡ
ΠΏΠ΅ΡΡΠΏΠ΅ΠΊΡΠΈΠ²Π½ΠΈΠΌΠΈ ΠΊΠ°Π½Π΄ΠΈΠ΄Π°ΡΠ°ΠΌΠΈ Π΄Π»Ρ Π²ΠΈΠΊΠΎΡΠΈΡΡΠ°Π½Π½Ρ Π² ΡΠΊΠΎΡΡΡ Π±Π°Ρ'ΡΡΠ½ΠΈΡ
ΠΌΠ°ΡΠ΅ΡΡΠ°Π»ΡΠ² Π΄Π»Ρ Π·Π°Ρ
ΠΎΡΠΎΠ½Π΅Π½Π½Ρ ΡΠ°Π΄ΡΠΎΠ°ΠΊΡΠΈΠ²Π½ΠΈΡ
Π²ΡΠ΄Ρ
ΠΎΠ΄ΡΠ². ΠΠ΅ΡΠΎΡ ΡΡΡΡ ΡΠΎΠ±ΠΎΡΠΈ Π±ΡΠ»ΠΎ ΠΎΡΡΠΈΠΌΠ°Π½Π½Ρ Π²ΠΈΡΠΎΠΊΠΎΡΡΠ»ΡΠ½ΠΎΡ SiC-ΠΊΠ΅ΡΠ°ΠΌΡΠΊΠΈ Π· Π²Π΄ΠΎΡΠΊΠΎΠ½Π°Π»Π΅Π½ΠΈΠΌΠΈ ΡΡΠ·ΠΈΡΠ½ΠΈΠΌΠΈ Ρ ΠΌΠ΅Ρ
Π°Π½ΡΡΠ½ΠΈΠΌΠΈ Π²Π»Π°ΡΡΠΈΠ²ΠΎΡΡΡΠΌΠΈ. ΠΠΈΡΠΎΠΊΡ ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΠΈ ΠΎΡΡΠΈΠΌΠ°Π½ΠΎΡ ΠΊΠ΅ΡΠ°ΠΌΡΠΊΠΈ Π²ΠΈΠ·Π½Π°ΡΠ°ΡΡΡΡΡ ΡΠΎΡΠΌΡΠ²Π°Π½Π½ΡΠΌ Π²ΠΈΡΠΎΠΊΠΎΡΡΠ»ΡΠ½ΠΎΡ Ρ ΠΌΠΎΠ½ΠΎΠ»ΡΡΠ½ΠΎΡ ΡΡΡΡΠΊΡΡΡΠΈ. ΠΠ΅ΡΠ°ΠΌΡΠΊΠ° ΠΊΠ°ΡΠ±ΡΠ΄Ρ ΠΊΡΠ΅ΠΌΠ½ΡΡ ΠΌΠ°Ρ ΠΏΠΎΠ»ΡΠΏΡΠ΅Π½Ρ ΠΌΠ΅Ρ
Π°Π½ΡΡΠ½Ρ ΠΌΡΡΠ½ΡΡΡΡ Ρ Π²ΠΈΡΠΎΠΊΡ ΡΠ²Π΅ΡΠ΄ΡΡΡΡ ΠΏΠΎ ΠΡΠΊΠΊΠ΅ΡΡΡ ΠΏΠΎΡΡΠ΄ΠΊΠ° 28,5 ΠΠa.ΠΠ΅ΡΠΊΠΈΡΠ»ΠΎΡΠΎΠ΄Π½ΡΠ΅ ΠΊΠ΅ΡΠ°ΠΌΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»Ρ Π΄Π΅ΠΌΠΎΠ½ΡΡΡΠΈΡΡΡΡ Π²ΡΡΠΎΠΊΠΈΠ΅ ΡΠΈΠ·ΠΈΠΊΠΎ-ΠΌΠ΅Ρ
Π°Π½ΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΡΠ²ΠΎΠΉΡΡΠ²Π°, ΠΊΠΎΡΡΠΎΠ·ΠΈΠΎΠ½Π½ΡΡ ΠΈ ΡΠ°Π΄ΠΈΠ°ΡΠΈΠΎΠ½Π½ΡΡ ΡΡΠΎΠΉΠΊΠΎΡΡΡ, Π΄Π΅Π»Π°ΡΡΠΈΠ΅ ΠΈΡ
ΠΏΠ΅ΡΡΠΏΠ΅ΠΊΡΠΈΠ²Π½ΡΠΌΠΈ ΠΊΠ°Π½Π΄ΠΈΠ΄Π°ΡΠ°ΠΌΠΈ Π΄Π»Ρ ΠΈΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½ΠΈΡ Π² ΠΊΠ°ΡΠ΅ΡΡΠ²Π΅ Π±Π°ΡΡΠ΅ΡΠ½ΡΡ
ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»ΠΎΠ² Π΄Π»Ρ Π·Π°Ρ
ΠΎΡΠΎΠ½Π΅Π½ΠΈΡ ΡΠ°Π΄ΠΈΠΎΠ°ΠΊΡΠΈΠ²Π½ΡΡ
ΠΎΡΡ
ΠΎΠ΄ΠΎΠ². Π¦Π΅Π»ΡΡ Π½Π°ΡΡΠΎΡΡΠ΅ΠΉ ΡΠ°Π±ΠΎΡΡ Π±ΡΠ»ΠΎ ΠΏΠΎΠ»ΡΡΠ΅Π½ΠΈΠ΅ Π²ΡΡΠΎΠΊΠΎΠΏΠ»ΠΎΡΠ½ΠΎΠΉ SiC-ΠΊΠ΅ΡΠ°ΠΌΠΈΠΊΠΈ Ρ ΡΡΠΎΠ²Π΅ΡΡΠ΅Π½ΡΡΠ²ΠΎΠ²Π°Π½Π½ΡΠΌΠΈ ΡΠΈΠ·ΠΈΡΠ΅ΡΠΊΠΈΠΌΠΈ ΠΈ ΠΌΠ΅Ρ
Π°Π½ΠΈΡΠ΅ΡΠΊΠΈΠΌΠΈ ΡΠ²ΠΎΠΉΡΡΠ²Π°ΠΌΠΈ. ΠΡΡΠΎΠΊΠΈΠ΅ ΠΏΠ°ΡΠ°ΠΌΠ΅ΡΡΡ ΠΏΠΎΠ»ΡΡΠ΅Π½Π½ΠΎΠΉ ΠΊΠ΅ΡΠ°ΠΌΠΈΠΊΠΈ ΠΎΠΏΡΠ΅Π΄Π΅Π»ΡΡΡΡΡ ΡΠΎΡΠΌΠΈΡΠΎΠ²Π°Π½ΠΈΠ΅ΠΌ Π²ΡΡΠΎΠΊΠΎΠΏΠ»ΠΎΡΠ½ΠΎΠΉ ΠΈ ΠΌΠΎΠ½ΠΎΠ»ΠΈΡΠ½ΠΎΠΉ ΡΡΡΡΠΊΡΡΡΡ. ΠΠ΅ΡΠ°ΠΌΠΈΠΊΠ° ΠΊΠ°ΡΠ±ΠΈΠ΄Π° ΠΊΡΠ΅ΠΌΠ½ΠΈΡ ΠΎΠ±Π»Π°Π΄Π°Π΅Ρ ΡΠ»ΡΡΡΠ΅Π½Π½ΠΎΠΉ ΠΌΠ΅Ρ
Π°Π½ΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΏΡΠΎΡΠ½ΠΎΡΡΡΡ ΠΈ Π²ΡΡΠΎΠΊΠΎΠΉ ΡΠ²Π΅ΡΠ΄ΠΎΡΡΡΡ ΠΏΠΎ ΠΠΈΠΊΠΊΠ΅ΡΡΡ ΠΏΠΎΡΡΠ΄ΠΊΠ° 28,5 ΠΠa
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