Abstract
Charcot-Marie-Tooth 1A (CMT1A) is the most common inherited neuropathy without a known therapy, which is caused by a 1.4 Mb duplication on human chromosome 17, which includes the gene ...encoding the peripheral myelin protein of 22 kDa (PMP22). Overexpressed PMP22 protein from its gene duplication is thought to cause demyelination and subsequently axonal degeneration in the peripheral nervous system (PNS). Here, we targeted TATA-box of human PMP22 promoter to normalize overexpressed PMP22 level in C22 mice, a mouse model of CMT1A harboring multiple copies of human PMP22. Direct local intraneural delivery of CRISPR/Cas9 designed to target TATA-box of PMP22 before the onset of disease, downregulates gene expression of PMP22 and preserves both myelin and axons. Notably, the same approach was effective in partial rescue of demyelination even after the onset of disease. Collectively, our data present a proof-of-concept that CRISPR/Cas9-mediated targeting of TATA-box can be utilized to treat CMT1A.
The long-standing challenge of designing and constructing new crystalline solid-state materials from molecular building blocks is just beginning to be addressed with success. A conceptual approach ...that requires the use of secondary building units to direct the assembly of ordered frameworks epitomizes this process: we call this approach reticular synthesis. This chemistry has yielded materials designed to have predetermined structures, compositions and properties. In particular, highly porous frameworks held together by strong metal-oxygen-carbon bonds and with exceptionally large surface area and capacity for gas storage have been prepared and their pore metrics systematically varied and functionalized.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This work is concerned with the kinetics of laser-induced reductive sintering of nonstoichiometric crystalline nickel oxide (NiO) nanoparticles (NPs) under ambient conditions. The mechanism of ...photophysical reductive sintering upon irradiation using a 514.5 nm continuous-wave (CW) laser on NiO NP thin films has been studied through modulating the laser power density and illumination time. Protons produced due to high-temperature decomposition of the solvent present in the NiO NP ink, oxygen vacancies in the NiO NPs, and electronic excitation in the NiO NPs by laser irradiation all affect the early stage of the reductive sintering process. Once NiO NPs are reduced by laser irradiation to Ni, they begin to coalesce, forming a conducting material. In situ optical and electrical measurements during the reductive sintering process take advantage of the distinct differences between the oxide and the metallic phases to monitor the transient evolution of the process. We observe four regimes: oxidation, reduction, sintering, and reoxidation. A characteristic time scale is assigned to each regime.
One of the outstanding challenges in the field of porous materials is the design and synthesis of chemical structures with exceptionally high surface areas. Such materials are of critical importance ...to many applications involving catalysis, separation and gas storage. The claim for the highest surface area of a disordered structure is for carbon, at 2,030 m2 g-1 (ref. 2). Until recently, the largest surface area of an ordered structure was that of zeolite Y, recorded at 904 m2 g-1 (ref. 3). But with the introduction of metal-organic framework materials, this has been exceeded, with values up to 3,000 m2 g-1 (refs 4-7). Despite this, no method of determining the upper limit in surface area for a material has yet been found. Here we present a general strategy that has allowed us to realize a structure having by far the highest surface area reported to date. We report the design, synthesis and properties of crystalline Zn4O(1,3,5-benzenetribenzoate)2, a new metal-organic framework with a surface area estimated at 4,500 m2 g-1. This framework, which we name MOF-177, combines this exceptional level of surface area with an ordered structure that has extra-large pores capable of binding polycyclic organic guest molecules-attributes not previously combined in one material.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
To determine how arterial spin labeling (ASL) measured perfusion relates to baseline metabolism, we compared resting state cerebral perfusion using pseudo-continuous ASL and cerebral glucose ...metabolism using 18F-FDG PET in 20 normal volunteers. Greater regional metabolism relative to perfusion was observed in the putamen, orbitofrontal and temporal lobes, whereas perfusion was relatively higher in the hippocampus and insula. In a region of interest analysis limited to gray matter, the overall mean correlation between perfusion and metabolism across voxels was r=0.43 with considerable regional variability. Cross-voxel correlations between relative perfusion and metabolism in mean ASL and PET images of all 20 subjects were the highest in the striatum (caudate: r=0.78; putamen: r=0.81), and the lowest in medial temporal structures (amygdala: r=0.087; hippocampus: r=−0.26). Correlations between mean relative perfusion and metabolism across 20 subjects were the highest in the striatum (caudate: r=0.76; putamen: r=0.58), temporal lobe (r=0.59), and frontal lobe (r=0.52), but very poor in all other structures (r<0.3), particularly in caudal structures such as the hippocampus (r=−0.0026), amygdala (r=0.18), and insula (r=0.14). Although there was good overall correlation between perfusion and glucose metabolism, regional variability should be considered when using either ASL or 18F-FDG PET as surrogate markers for neural activity.
BACKGROUND:Hyaluronic acid–based dermal fillers have gained rapid acceptance for treating facial wrinkles and deep tissue folds. Although their space-filling properties are well understood, this ...study evaluates the cellular and molecular changes in skin, as a secondary effect, following injection of a commercially available, 24-mg/ml, cross-linked hyaluronic acid–based filler (HYC-24L+) in a rodent model.
METHODS:Sprague-Dawley rats, aged 2 to 4 months, were injected intradermally with 20 μl of HYC-24L+ using a linear threading technique and followed to 12 weeks after injection. Untreated skin and saline injection were used as study controls. Enzyme-linked immunosorbent assay and reverse-transcriptase polymerase chain reaction methods were used to investigate changes in the expression of several extracellular matrix proteins and genes over time.
RESULTS:HYC-24L+ significantly increased the protein expression levels of collagen types I and III in rat dermal tissue for up to 12 weeks. The ratio of collagen type III to type I protein, however, remained unchanged, suggesting maintenance of collagen homeostasis. A significant increase in dermal elastin after HYC-24L+ injection was also observed. Gene expression analysis confirmed that several genes associated with extracellular matrix production and assembly were also transiently up-regulated, and that these changes temporally preceded those observed at the protein level.
CONCLUSION:In addition to its well-understood space-filling function, as a secondary effect, the authors demonstrate that HYC-24L+ stimulates the production of several extracellular matrix components, including dermal collagen and elastin.
An electro-thermal annealing (ETA) method, which uses an electrical pulse of less than 100 ns, was developed to improve the electrical performance of array-level amorphous-oxide-semiconductor (AOS) ...thin-film transistors (TFTs). The practicality of the ETA method was experimentally demonstrated with transparent amorphous In–Ga–Zn-O (a-IGZO) TFTs. The overall electrical performance metrics were boosted by the proposed method: up to 205% for the trans-conductance (g m ), 158% for the linear current (I linear ), and 206% for the subthreshold swing (SS). The performance enhancement were interpreted by X-ray photoelectron microscopy (XPS), showing a reduction of oxygen vacancies in a-IGZO after the ETA. Furthermore, by virtue of the extremely short operation time (80 ns) of ETA, which neither provokes a delay of the mandatory TFTs operation such as addressing operation for the display refresh nor demands extra physical treatment, the semipermanent use of displays can be realized.
Nonalcoholic fatty liver is involved in the development of nonalcoholic steatohepatitis and chronic liver injury. Impairment of hepatic transsulfuration reactions is suggested to be critically linked ...with alcoholic liver injury, but its role in nonalcoholic fatty liver remains unknown. We examined the early changes in sulfur-amino acid metabolism and their implication in nonalcoholic fatty liver disease (NAFLD). Male rats were provided with a standard liquid diet or a high-fat liquid diet (HF) for 3 wk. An additional group of rats received the HF diet supplemented with betaine (1%). HF diet intake elevated hepatic triglyceride and serum tumor necrosis factor-α (TNFα) concentrations. Antioxidant capacity of liver cytosol against hydroxyl and peroxyl radicals was reduced significantly. Hepatic S-adenosylmethionine (SAM) and glutathione (GSH) decreased, but hypotaurine and taurine concentrations increased. Methionine adenosyltransferase (MAT) activity, not its concentration, was depressed, whereas both activity and concentration of cysteine dioxygenase and GSH S-transferase were elevated. Betaine supplementation of the HF diet inhibited hepatic fat accumulation and serum TNFα elevation. The decrease in cytosolic antioxidant capacity was also prevented. MAT activity and its concentration were induced significantly. Hepatic SAM and GSH increased and elevation of hypotaurine and taurine was depressed. The results indicate that the metabolism of S-containing substances is significantly disturbed by the HF diet, suggesting a causal role of impairment of hepatic transsulfuration reactions in NAFLD. Betaine supplementation protects the liver from nonalcoholic steatosis and oxidative stress most probably via its effects on the transsulfuration reactions.
Primitive myxoid mesenchymal tumor of infancy (PMMTI) is a rare tumor with <20 cases reported to date. Recently PMMTI tumors have been found to harbor
internal tandem duplication (ITD), the same ...genetic alteration detected in clear cell sarcoma of the kidney (CCSK). Complete surgical resection of PMMTI is often curative, but no standard of care has been established for unresectable tumors. We describe a female patient who presented at 13 months of age with a paraspinal mass and spinal cord compression. Histology was consistent with PMMTI, and the tumor was found to harbor
ITD. The patient experienced disease recurrences after multiple surgical resections. After failing to respond to vincristine and actinomycin therapy, the patient demonstrated a nearly complete response to a doxorubicin-containing chemotherapy regimen. The patient's therapy was consolidated with proton beam radiotherapy, and she has remained in remission for >12 months after the conclusion of therapy. This case confirms
ITD as a key finding in PMMTI. The therapeutic approach described here is similar to that used for CCSK and provides a model for the treatment of PMMTI not amenable to complete surgical resection.
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