Ryanodine receptors contribute to the induction of nociceptive input-evoked long-term potentiation in the rat spinal cord slice

<p>Abstract</p> <p>Background</p> <p>Our previous study demonstrated that nitric oxide (NO) contributes to long-term potentiation (LTP) of C-fiber-evoked field potentials by tetanic stimulation of the sciatic nerve in the spinal cord <it>in vivo</it>. Ryanodine receptor (RyR) is a downstream target for NO. The present study further explored the role of RyR in synaptic plasticity of the spinal pain pathway.</p> <p>Results</p> <p>By means of field potential recordings in the adult male rat <it>in vivo</it>, we showed that RyR antagonist reduced LTP of C-fiber-evoked responses in the spinal dorsal horn by tetanic stimulation of the sciatic nerve. Using spinal cord slice preparations and field potential recordings from superficial dorsal horn, high frequency stimulation of Lissauer's tract (LT) stably induced LTP of field excitatory postsynaptic potentials (fEPSPs). Perfusion of RyR antagonists blocked the induction of LT stimulation-evoked spinal LTP, while Ins(1,4,5)P3 receptor (IP₃R) antagonist had no significant effect on LTP induction. Moreover, activation of RyRs by caffeine without high frequency stimulation induced a long-term potentiation in the presence of bicuculline methiodide and strychnine. Further, in patch-clamp recordings from superficial dorsal horn neurons, activation of RyRs resulted in a large increase in the frequency of miniature EPSCs (mEPSCs). Immunohistochemical study showed that RyRs were expressed in the dorsal root ganglion (DRG) neurons. Likewise, calcium imaging in small DRG neurons illustrated that activation of RyRs elevated [Ca²⁺]_iin small DRG neurons.</p> <p>Conclusions</p> <p>These data indicate that activation of presynaptic RyRs play a crucial role in the induction of LTP in the spinal pain pathway, probably through enhancement of transmitter release.</p

The semi-leptonic form factors of Λb→Λc\Lambda_{b}\to\Lambda_{c} and Ξb→Ξc\Xi_{b}\to\Xi_{c} in QCD sum rules

In this work, the full leading order results of the form factors for $\Xi_{b}\to\Xi_{c}$ and $\Lambda_{b}\to\Lambda_{c}$ are obtained in QCD sum rules. Contributions from up to dim-5 have been considered. For completeness, we also study the two-point correlation function to obtain the pole residues of $\Xi_{Q}$ and $\Lambda_{Q}$, and higher accuracy is achieved. For the three-point correlation function, since stable Borel regions can not be found, about $20\%$ uncertainties are introduced for the form factors of $\Xi_{b}\to\Xi_{c}$ and $\Lambda_{b}\to\Lambda_{c}$. Our results for the form factors are consistent with those of the Lattice QCD within errors.Comment: 17 pages, 5 figure

Testing and Data Reduction of the Chinese Small Telescope Array (CSTAR) for Dome A, Antarctica

The Chinese Small Telescope ARray (hereinafter CSTAR) is the first Chinese astronomical instrument on the Antarctic ice cap. The low temperature and low pressure testing of the data acquisition system was carried out in a laboratory refrigerator and on the 4500m Pamirs high plateau, respectively. The results from the final four nights of test observations demonstrated that CSTAR was ready for operation at Dome A, Antarctica. In this paper we present a description of CSTAR and the performance derived from the test observations.Comment: Accepted Research in Astronomy and Astrophysics (RAA) 1 Latex file and 20 figure

p21WAF1 and hypoxia/reoxygenation-induced premature senescence of H9c2 cardiomyocytes

We have previously reported on hypoxia/reoxygenation-induced premature senescence in neonatal rat cardiomyocytes. In this research, we investigated the effects of p21WAF1 (p21) in hypoxia/reoxygenation-induced senescence, using H9c2 cells. A plasmid overexpressing wild type p21WAF1 and a plasmid expressing small hairpin RNA (shRNA) targeting p21WAF1 were constructed, and transfected into H9c2 cells to control the p21 expression. Hypoxia/reoxygenation conditions were 1% O2 and 5% CO2, balancing the incubator chamber with N2 for 6 h (hypoxia 6 h), then 21% oxygen for 8 h (reoxygenation 8 h). Cell cycle was examined using flow cytometry. Senescence was assessed using &#946;-galactosidase staining. The expression of p53, p21, p16INK4a, and cyclin D1 was assayed using Western blotting. At hypoxia 6 h, cells overexpressing p21 had a larger G1 distribution, stronger &#946;-galactosidase activity, and lower cyclin D1 expression compared to control cells, while the opposite results and higher p53 expression were obtained in p21-knockdown cells. At reoxygenation 8 h, p21-silenced cells had a smaller percentage of G1 cells, weaker &#946;-galactosidase activity and lower 16INK4a expression, and higher cyclin D1 expression, but the overexpression group showed no difference. Taken together, this data implies that p21WAF1 is important for the hypoxia phase, but not the reoxygenation phase, in the H9c2 senescence process. (Folia Histochemica et Cytobiologica 2011, Vol. 49, No. 3, 445&#8211;451

Is Floppy Eyelid Syndrome More Prevalent in Obstructive Sleep Apnea Syndrome Patients?

Controversial findings are reported about the relationship between floppy eyelid syndrome (FES) and obstructive sleep apnea syndrome (OSAS). The main goal of this study was to evaluate whether FES is more prevalent in OSAS patients by performing a meta-analysis. A comprehensive literature search of Pubmed, Embase, and Cochrane databases was performed. Only studies related to the prevalence of FES in OSAS were included in the meta-analysis. We estimated a pooled odds ratio (OR) for the prevalence of FES in OSAS. In total, 6 studies with 767 participants met the inclusion criteria. Using a fixed-effects model, the pooled OR was 4.12. The test for the overall effect revealed that FES was statistically prevalent in OSAS patients when compared with that in non-OSAS subjects (Z=4.98, p<0.00001). In the subgroup analysis by OSAS severity, the incidence of FES in OSAS increased with severity of OSAS as indicated with increased OR values (OR = 2.56, 4.62, and 7.64 for mild, moderate, and severe OSAS). In conclusion, the results indicate that FES is more prevalent in OSAS patients. However, this result was based only on unadjusted estimates. Prospective cohort studies are needed to determine whether OSAS is an independent risk factor for FES

Goshawk: A Novel Efficient, Robust and Flexible Blockchain Protocol

Proof of Work (PoW), a fundamental blockchain protocol, has been widely applied and thoroughly testifed in various decentralized cryptocurrencies, due to its intriguing merits including trustworthy sustainability, robustness against sybil attack, delicate incentive-compatibility, and openness to any participant. Meanwhile, PoW-powered blockchains still su&#64256;er from poor efciency, potential selfsh mining, to-be-optimized fairness and extreme inconvenience of protocol upgrading. Therefore, it is of great interest to design new PoW-based blockchain protocol to address or relieve the above issues so as to make it more applicable and feasible. To do so, frstly we take advantage of the basic framework (i.e., two-layer chain structure) adopted in Bitcoin-NG which was introduced by Eyal et al. to extend the throughput of Bitcoin-derived blockchains signifcantly via blocks of a two-layer structure, inheriting the high throughput merit while ridding o&#64256; the vulnerability to the attack of microblock swamping in Bitcoin-NG as well as attaining a better fairness property, by presenting two-level mining mechanism and incorporating this mechanism into the two-layer chain structure. Furthermore, to tackle the selfsh mining issue, strengthen the robustness against the “51%” attack of PoW miners, and o&#64256;er the &#64258;exibility for future protocol updating e&#64256;ectively, we borrow the idea of ticket-voting mechanism from DASH and Decred, and combine it with our improved structure elaborately to build a novel efcient, robust and &#64258;exible blockchain protocol (named Goshawk). Last but not the least, this scheme has been implemented and deployed in the testnet of the public blockchain project Hcash for months, and has demonstrated its stability and high efciency with such real-world test