1,987 research outputs found
AAV-KLF7 Promotes Descending Propriospinal Neuron Axonal Plasticity after Spinal Cord Injury
DPSN axons mediate and maintain a variety of normal spinal functions. Unsurprisingly, DPSN tracts have been shown to mediate functional recovery following SCI. KLF7 could contribute to CST axon plasticity after spinal cord injury. In the present study, we assessed whether KLF7 could effectively promote DPSN axon regeneration and synapse formation following SCI. An AAV-KLF7 construct was used to overexpress KLF7. In vitro, KLF7 and target proteins were successfully elevated and axonal outgrowth was enhanced. In vivo, young adult C57BL/6 mice received a T10 contusion followed by an AAV-KLF7 injection at the T7–9 levels above the lesion. Five weeks later, overexpression of KLF7 was expressed in DPSN. KLF7 and KLF7 target genes (NGF, TrkA, GAP43, and P0) were detectably increased in the injured spinal cord. Myelin sparring at the lesion site, DPSN axonal regeneration and synapse formation, muscle weight, motor endplate morphology, and functional parameters were all additionally improved by KLF7 treatment. Our findings suggest that KLF7 promotes DPSN axonal plasticity and the formation of synapses with motor neurons at the caudal spinal cord, leading to improved functional recovery and further supporting the potential of AAV-KLF7 as a therapeutic agent for spinal cord injury
KLF7-transfected Schwann cell graft transplantation promotes sciatic nerve regeneration
Our former study demonstrated that Krüppel-like Factor 7 (KLF7) is a transcription factor that stimulates axonal regeneration after peripheral nerve injury. Currently, we used a gene therapy approach to overexpress KLF7 in Schwann cells (SCs) and assessed whether KLF7-transfected SCs graft could promote sciatic nerve regeneration. SCs were transfected by adeno-associated virus 2 (AAV2)-KLF7 in vitro. Mice were allografted by an acellular nerve (ANA) with either an injection of DMEM (ANA group), SCs (ANA + SCs group) or AAV2-KLF7-transfected SCs (ANA + KLF7-SCs group) to assess repair of a sciatic nerve gap. The results indicate that KLF7 overexpression promoted the proliferation of both transfected SCs and native SCs. The neurite length of the dorsal root ganglia (DRG) explants was enhanced. Several beneficial effects were detected in the ANA + KLF7-SCs group including an increase in the compound action potential amplitude, sciatic function index score, enhanced expression of PKH26-labeling transplant SCs, peripheral myelin protein 0, neurofilaments, S-100, and myelinated regeneration nerve. Additionally, HRP-labeled motoneurons in the spinal cord, CTB-labeled sensory neurons in the DRG, motor endplate density and the weight ratios of target muscles were increased by the treatment while thermal hyperalgesia was diminished. Finally, expression of KLF7, NGF, GAP43, TrkA and TrkB were enhanced in the grafted SCs, which may indicate that several signal pathways may be involved in conferring the beneficial effects from KLF7 overexpression. We concluded that KLF7-overexpressing SCs promoted axonal regeneration of the peripheral nerve and enhanced myelination, which collectively proved KLF-SCs as a novel therapeutic strategy for injured nerves
Purification, compositional analysis and antioxidant properties of polysaccharides from black ginseng
Purpose: To extract, purify black ginseng polysaccharides, and study their compositional analysis and antioxidant properties.Methods: Crude polysaccharides from black ginseng were prepared by hot water extraction and subjected to chromatographic purification on Sephadex G-75 and DEAE-cellulose and Sephadex G-75 columns to yield 4 polysaccharide components: BGP-60, BGP-65, BGP-70 and BGP-80. The BGPs were characterized by chemical analysis, gel permeation chromatography (GPC), gas chromatographymass spectrometry (GC-MS), and Fourier transform-infrared spectroscopy (FT-IR). Finally, the in vitro antioxidant activities of the BGPs were determined through their capacities to scavenge superoxide anion, as well as 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radicals.Results: The four fractions designated BGP-60, BGP-65, BGP-70 and BGP-80 were polysaccharides with glucose as the main component. They were acidic in nature, with estimated molecular weights (MWs) of 28.6, 26.7, 11.4 and 3.05 kDa, respectively. Fractions BGP-60, BGP-65 and BGP-80 had α- type glycosidic linkage, whereas BGP-70 had β-type glycosidic linkage. Compared with vitamin C (vit C), it was found that BGP-60, BGP-65, BGP-70 and BGP-80 had strong potential antioxidant activities; BGP-60 exhibited a stronger antioxidant activity than BGP-65, BGP-70 or BGP-80 against DPPH and superoxide anion radicals, while BGP-65 had the highest antioxidant activity against hydroxyl radical.Conclusion: These results suggest that BGPs may be beneficial in the development and manufacture as potential therapeutic agents and functional foods.Keywords: Black ginseng, Polysaccharides, Purification, Antioxidant activity, Functional food
Emulating power spectra for pre- and post-reconstructed galaxy samples
The small-scale linear information in galaxy samples typically lost during
non-linear growth can be restored to a certain level by the density field
reconstruction, which has been demonstrated for improving the precision of the
baryon acoustic oscillations (BAO) measurements. As proposed in the literature,
a joint analysis of the power spectrum before and after the reconstruction
enables an efficient extraction of information carried by high-order
statistics. However, the statistics of the post-reconstruction density field
are difficult to model. In this work, we circumvent this issue by developing an
accurate emulator for the pre-reconstructed, post-reconstructed, and cross
power spectra (, , ) up to
based on the \textsc{Dark Quest} N-body simulations.
The accuracy of the emulator is at percent level, namely, the error of the
emulated monopole and quadrupole of the power spectra is less than and
of the ground truth, respectively. A fit to an example power spectra
using the emulator shows that the constraints on cosmological parameters get
largely improved using ++ with
, compared to that derived from alone, namely, the constraints on (, , ) are
tightened by , and the uncertainties of the derived BAO and RSD
parameters (, , ) shrink by , respectively. This highlights the complementarity among , and , which demonstrates the efficiency
and practicability of a joint , and
analysis for cosmological implications.Comment: 15 pages, 8 figures, 2 table
Acupuncture Attenuates Anxiety-Like Behavior by Normalizing Amygdaloid Catecholamines during Ethanol Withdrawal in Rats
Previously, we demonstrated acupuncture at acupoint HT7 (Shen-Men) attenuated ethanol withdrawal syndrome by normalizing the dopamine release in nucleus accumbens shell. In the present study, we investigated the effect of acupuncture on anxiety-like behavior in rats and its relevant mechanism by studying neuro-endocrine parameters during ethanol withdrawal. Rats were treated with 3 g kg−1day−1 of ethanol (20%, w/v) or saline by intraperitoneal injections for 28 days. The rats undergoing ethanol withdrawal exhibited anxiety-like behavior 72 h after the last dose of ethanol characterized by the decrease of time spent in the open arms of the elevated plus maze compared with the saline-treated rats (P < .05). Radioimmunoassay exhibited there were notably increased concentrations of plasma corticosterone in ethanol-withdrawn rats compared with saline-treated rats (P < .05). Additionally, high performance liquid chromatography analysis also showed the levels of norepinephrine and 3-methoxy-4-hydroxy-phenylglycol were markedly increased while the levels of dopamine and 3,4-dihydroxyphenylacetic acid were significantly decreased in the central nucleus of the amygdala of ethanol-withdrawn rats compared with saline-treated rats (P < .01). Acupuncture groups were treated with acupuncture at acupoint HT7 or PC6 (Nei-Guan). Acupuncture at HT7 but not PC6 greatly attenuated the anxiety-like behavior during ethanol withdrawal as evidenced by significant increases in the percentage of time spent in open arms (P < .05). In the meantime, acupuncture at HT7 also markedly inhibited the alterations of neuro-endocrine parameters induced by ethanol withdrawal (P < .05). These results suggest that acupuncture may attenuate anxiety-like behavior during ethanol withdrawal through regulation of neuro-endocrine system
The superhydrophobicity of polymer surfaces: Recent developments
Superhydrophobicity is the extreme water repellence of highly textured surfaces. The field of superhydrophobicity research has reached a stage where huge numbers of candidate treatments have been proposed and jumps have been made in theoretically describing them. There now seems to be a move to more practical concerns and to considering the demands of individual applications instead of more general cases. With these developments, polymeric surfaces with their huge variety of properties have come to the fore and are fast becoming the material of choice for designing, developing, and producing superhydrophobic surfaces. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 49: 1203–1217, 201
Vagus nerve stimulation for refractory posttraumatic epilepsy: Efficacy and predictors of seizure outcome
BackgroundTraumatic brain injury (TBI) has been recognized as an important and common cause of epilepsy since antiquity. Posttraumatic epilepsy (PTE) is usually associated with drug resistance and poor surgical outcomes, thereby increasing the burden of the illness on patients and their families. Vagus nerve stimulation (VNS) is an adjunctive treatment for medically refractory epilepsy. This study aimed to determine the efficacy of VNS for refractory PTE and to initially evaluate the potential predictors of efficacy.MethodsWe retrospectively collected the outcomes of VNS with at least a 1-year follow-up in all patients with refractory PTE. Subgroups were classified as responders and non-responders according to the efficacy of VNS (≥50% or <50% reduction in seizure frequency). Preoperative data were analyzed to screen for potential predictors of VNS efficacy.ResultsIn total, forty-five patients with refractory PTE who underwent VNS therapy were enrolled. Responders were found in 64.4% of patients, and 15.6% of patients achieved seizure freedom at the last follow-up. In addition, the responder rate increased over time, with 37.8, 44.4, 60, and 67.6% at the 3-, 6-, 12-, and 24-month follow-ups, respectively. After multivariate analysis, generalized interictal epileptic discharges (IEDs) were found to be a negative predictor (OR: 4.861, 95% CI: 1.145–20.632) of VNS efficacy.ConclusionThe results indicated that VNS therapy was effective in refractory PTE patients and was well tolerated over a 1-year follow-up period. Patients with focal or multifocal IEDs were recognized to have better efficacy after VNS therapy
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