AAV-mediated transduction and targeting of retinal bipolar cells with improved mGluR6 promoters in rodents and primates.

Adeno-associated virus (AAV) vectors have been a powerful gene delivery vehicle to the retina for basic research and gene therapy. For many of these applications, achieving cell type-specific targeting and high transduction efficiency is desired. Recently, there has been increasing interest in AAV-mediated gene targeting to specific retinal bipolar cell types. A 200-bp enhancer in combination with a basal SV40 promoter has been commonly used to target transgenes into ON-type bipolar cells. In the current study, we searched for additional cis-regulatory elements in the mGluR6 gene for improving AAV-mediated transduction efficiency into retinal bipolar cells. Our results showed that the combination of the endogenous mGluR6 promoter with additional enhancers in the introns of the mGluR6 gene markedly enhanced AAV transduction efficiency as well as made the targeting more selective for rod bipolar cells in mice. Furthermore, the AAV vectors with the improved promoter could target to ON bipolar cells with robust transduction efficiency in the parafovea and the far peripheral retina of marmoset monkeys. The improved mGluR6 promoter constructs could provide a valuable tool for genetic manipulation in rod bipolar cells in mice and facilitate clinical applications for ON bipolar cell-based gene therapies.

Spin-orbit interactions and the nematicity observed in the fe-based superconductors.

High-resolution angle-resolved photoelectron spectroscopy is used to examine the electronic band structure of FeTe_{0.5}Se_{0.5} near the Brillouin zone center. A consistent separation of the α_{1} and α_{2} bands is observed with little k_{z} dependence of the α_{1} band. First-principles calculations for bulk and thin films demonstrate that the antiferromagnetic coupling between the Fe atoms and hybridization-induced spin-orbit effects lifts the degeneracy of the Fe d_{xz} and d_{yz} orbitals at the zone center leading to orbital ordering. These experimental and computational results provide a natural microscopic basis for the nematicity observed in the Fe-based superconductors.

Signal-processing electronics for stable and sensitive weak-field atomic vector magnetometers.

We present the electronics developed for a sensitive and stable atomic vector magnetometer used in low-field detections. These electronics are required to be not only highly reliable and sophisticated for signal processing but also compact in size and low cost in resource consumption for the purpose of miniaturization. In addition, this magnetometer works with multiple modulations, where the interferences between harmonics of modulation fields often disturb the long-term measurements of the sensor. We work out a robust method to eliminate this problem by choosing the modulation frequencies with separations to match the minimum response points of the low-pass filters used in the demodulation processes. We validate the performance of the electronics and the frequency-selection scheme of the modulation fields with corresponding experimental results.

Photoemission spectroscopy of magnetic and nonmagnetic impurities on the surface of the Bi2Se3 topological insulator.

Dirac-like surface states on surfaces of topological insulators have a chiral spin structure that suppresses backscattering and protects the coherence of these states in the presence of nonmagnetic scatterers. In contrast, magnetic scatterers should open the backscattering channel via the spin-flip processes and degrade the state's coherence. We present angle-resolved photoemission spectroscopy studies of the electronic structure and the scattering rates upon the adsorption of various magnetic and nonmagnetic impurities on the surface of Bi2Se3, a model topological insulator. We reveal a remarkable insensitivity of the topological surface state to both nonmagnetic and magnetic impurities in the low impurity concentration regime. Scattering channels open up with the emergence of hexagonal warping in the high-doping regime, irrespective of the impurity's magnetic moment.

Measurement of an exceptionally weak electron-phonon coupling on the surface of the topological insulator Bi2Se3 using angle-resolved photoemission spectroscopy.

Gapless surface states on topological insulators are protected from elastic scattering on nonmagnetic impurities which makes them promising candidates for low-power electronic applications. However, for widespread applications, these states should have to remain coherent at ambient temperatures. Here, we studied temperature dependence of the electronic structure and the scattering rates on the surface of a model topological insulator, Bi2Se3, by high-resolution angle-resolved photoemission spectroscopy. We found an extremely weak broadening of the topological surface state with temperature and no anomalies in the state's dispersion, indicating exceptionally weak electron-phonon coupling. Our results demonstrate that the topological surface state is protected not only from elastic scattering on impurities, but also from scattering on low-energy phonons, suggesting that topological insulators could serve as a basis for room-temperature electronic devices.

Identity and virulence properties of Aeromonas isolates from diseased fish, healthy controls and water environment in China.

AIMS: To investigate the species distribution in Aeromonas isolates from diseased fish, healthy controls and water environment in China; to evaluate the frequency of the aerolysin (aer), cytotonic enterotoxin (alt), cytotoxic enterotoxin (act), temperature-sensitive protease (eprCAI) and serine protease (ahp) genes in Aeromonas isolates; and to determine the potential pathogenicity of these isolates. METHODS AND RESULTS: Two hundred and two Aeromonas isolates from diseased fish (n = 42), healthy fish (n = 120) and water environment (n = 40) in China were identified to species levels based on sequencing of the housekeeping gene gyrB, while the distribution of five virulence factors, including aer, alt, act, eprCAI and ahp, was investigated by PCR. Aeromonas veronii (25/42; 60%) and Aeromonas hydrophila (14/42; 33%) were the species most commonly isolated from diseased fish, while Aer. veronii was the most common species in healthy fish (90/120; 75%) and water samples (25/40; 62·5%). All the five virulence genes were present in 9% (19/202), among which 10 strains were from diseased fish and nine were identified as Aer. hydrophila. For the strains carrying five virulence genes, the average 50% lethal doses (LD(50s) ) of strains from diseased fish were lower when compared with the strains from healthy fish and water environment. CONCLUSIONS: Aeromonas veronii is the most common species, but no significant difference exists in the isolates obtained from diseased fish and from healthy fish. However, Aer. hydrophila isolates were significantly more frequent from diseased fish than from healthy fish. aer+alt+act+eprCAI+ ahp+ was more frequent virulence genotype in Aeromonas isolates from diseased fish than from healthy fish and water environment, and the aer+alt+act+eprCAI+ahp+ isolates were more virulent to zebrafish comparing to the other genetic profiles. SIGNIFICANT AND IMPACT OF THE STUDY: Aeromonas species in aquatic environments are various and have considerable virulence potential, and therefore, there is a need for more careful and intensive epidemiology studies.

Electronic structure of superconducting KC8 and nonsuperconducting LiC6 graphite intercalation compounds: evidence for a graphene-sheet-driven superconducting state.

We have performed photoemission studies of the electronic structure in LiC(6) and KC(8), a nonsuperconducting and a superconducting graphite intercalation compound, respectively. We have found that the charge transfer from the intercalant layers to graphene layers is larger in KC(8) than in LiC(6), opposite of what might be expected from their chemical composition. We have also measured the strength of the electron-phonon interaction on the graphene-derived Fermi surface to carbon derived phonons in both materials and found that it follows a universal trend where the coupling strength and superconductivity monotonically increase with the filling of graphene π(*) states. This correlation suggests that both graphene-derived electrons and graphene-derived phonons are crucial for superconductivity in graphite intercalation compounds.

Electronic structure of the topological insulator Bi2Se3 using angle-resolved photoemission spectroscopy: evidence for a nearly full surface spin polarization.

We performed high-resolution spin- and angle-resolved photoemission spectroscopy studies of the electronic structure and the spin texture on the surface of Bi2Se3, a model TI. By tuning the photon energy, we found that the topological surface state is well separated from the bulk states in the vicinity of kz = Z plane of the bulk Brillouin zone. The spin-resolved measurements in that region indicate a very high degree of spin polarization of the surface state, ~0.75, much higher than previously reported. Our results demonstrate that the topological surface state on Bi2Se3 is highly spin polarized and that the dominant factors limiting the polarization are mainly extrinsic.

Reconstructed Fermi surface of underdoped Bi2Sr2CaCu2O(8+δ) cuprate superconductors.

The Fermi surface topologies of underdoped samples of the high-T(c) superconductor Bi2Sr2CaCu2O(8+δ) have been measured with angle resolved photoemission. By examining thermally excited states above the Fermi level, we show that the observed Fermi surfaces in the pseudogap phase are actually components of fully enclosed hole pockets. The spectral weight of these pockets is vanishingly small at the magnetic zone boundary, creating the illusion of Fermi "arcs." The area of the pockets as measured in this study is consistent with the doping level, and hence carrier density, of the samples measured. Furthermore, the shape and area of the pockets is well reproduced by phenomenological models of the pseudogap phase as a spin liquid.

[Anatomical relationship between fascia propria of the rectum and visceral pelvic fascia in the view of continuity of fasciae].

Objective: To perform an anatomical observation on the extension of the mesocolon to the mesorectum and the continuity of the fasciae lining the abdomen and pelvis, in order to clarify the appropriate surgical plane of total mesorectal excision. Methods: This is an descriptive study. The operation videos of 61 cases (28 males, 33 females, median age of 61) were collected. All the patients underwent laparoscopic colorectal surgery from January 2018 to December 2018 in Yangpu Hospital, including low anterior resection for rectal cancer in 25 cases, left hemicolectomy for descending colon cancer in 15 cases, and subtotal resection of the colon for intractable constipation in 21 cases. Among these 21 constipation patients, 8 received additional modified Duhamel surgeries. Gross anatomy was performed on 24 adult cadavers provided by Department of Anatomy, Shanghai Jiaotong University School of Medicine, including 23 formalin-fixed and 1 fresh cadaver (12 males, 12 females). Sixty-one patients and 24 cadavers had no previous abdominal or pelvic surgical history. The anatomy and extension of fasciae related to descending colon, sigmoid colon and rectum, especially the morphology of Toldt fascia, and the continuities of mesocolon and mesorectum were observed carefully. The distribution characteristics of the fasciae and anatomical landmarks during laparoscopic surgery were recorded and described. Results: The anatomical study on 24 cadavers showed that visceral fascia was the densest connective tissue in the pelvic, posterolateral to the rectum, and stretched as a hammock to lift all pelvic organs. Among 61 patients undergoing laparoscopic surgery, 36 (59.0%) needed to free the left colon during operation, and Toldt fascia in the descending colon segment presented as potential, avascular and extensible loose connective tissue plane between the mesocolon and posterior Gerota fascia; 33 (54.1%) needed to free the rectum during operation, and Toldt fascia extended downward to pelvis as loose connective tissue between the fascia propria of the rectum and visceral fascia; the fascia propria of the rectum exposed completely in 32 (32/33, 97.0%) cases, which ran downward and fused with visceral fascia at the level of the fourth sacral vertebra. The anatomy of 24 cadavers also showed that fascia propria of the rectum fused with visceral fascia at the level of Waldeyer fascia. The fusion line of these two fasciae was supposed to be the extension of Waldeyer fascia. There were two avascular planes behind the rectum: one between the fascia propria of the rectum and visceral fascia, and the other between the visceral fascia and parietal fascia. In 8 constipation cases undergoing laparoscopic subtotal colon resection plus modified Duhamel operation, both mesocolon and mesorectum needed to be mobilized. It was obvious that the mesocolon of descending colon extended and became the mesocolon of sigmoid colon, and ran further into the pelvic and became the mesorectum. The colon fascia of descending colon served as the natural boundary of mesocolon extended downward as the fascia of sigmoid colon and the fascia propria of the rectum, respectively. Toldt fascia locating between mesocolon of descending colon and Gerota fascia extended to pelvis as the 'presacral space' between the fascia propria of the rectum and visceral fascia. Gerota fascia in descending colon segment extended as urogenital fascia in sigmoid colon segment and visceral fascia in the pelvis, respectively. In the cadaver anatomy study, the visceral fascia served as a corridor carrying the hypogastric nerve, and ureter was observed in 23 (23/24, 95.8%) cases. The visceral fascia passed from posterior to anterior lateral of rectum, fusing with Denonvilliers fascia in a fan shape. The pelvic plexus located exactly external to the junction of visceral fascia and Denonvilliers fascia. Pelvic splanchnic nerves went through the parietal fascia toward to the inferolateral of the pelvic plexus. Conclusion: Fascia propria of the rectum and the visceral pelvic fascia are two independent layers of fascia, and the TME surgical plane is between the fascia propria of the rectum and visceral pelvic fascia instead of between the visceral and the parietal pelvic fascia.

T-type Ca(2+) channels mediate neurotransmitter release in retinal bipolar cells.

Transmitter release in neurons is thought to be mediated exclusively by high-voltage-activated (HVA) Ca(2+) channels. However, we now report that, in retinal bipolar cells, low-voltage-activated (LVA) Ca(2+) channels also mediate neurotransmitter release. Bipolar cells are specialized neurons that release neurotransmitter in response to graded depolarizations. Here we show that these cells express T-type Ca(2+) channel subunits and functional LVA Ca(2+) currents sensitive to mibefradil. Activation of these currents results in Ca(2+) influx into presynaptic terminals and exocytosis, which we detected as a capacitance increase in isolated terminals and the appearance of reciprocal currents in retinal slices. The involvement of T-type Ca(2+) channels in bipolar cell transmitter release may contribute to retinal information processing.

Effect of nitric oxide production on the redox modulatory site of the NMDA receptor-channel complex.

Nitric oxide (NO) is an important messenger both systemically and in the CNS. In digital Ca2+ imaging and patch-clamp experiments, clinically available nitroso compounds that generate NO are shown to inhibit responses mediated by the NMDA subtype of the glutamate receptor on rat cortical neurons in vitro. A mechanism of action for this effect was investigated by using the specific NO-generating agent S-nitrosocysteine. We propose that free sulfhydryl groups on the NMDA receptor-channel complex react to form one or more S-nitrosothiols in the presence of NO. If vicinal thiol groups react in this manner, they can form a disulfide bond(s), which is thought to constitute the redox modulatory site of the receptor, resulting in a relatively persistent blockade of NMDA responses. These reactions with NO can afford protection from NMDA receptor-mediated neurotoxicity. Our results demonstrate a new pathway for NO regulation of physiological function that is not via cGMP, but instead involves reactions with membrane-bound thiol groups on the NMDA receptor-channel complex.

LINC00324 exerts tumor-promoting functions in lung adenocarcinoma via targeting miR-615-5p/AKT1 axis.

OBJECTIVE: The underlying mechanism of long non-coding RNA (lncRNA) in lung adenocarcinoma (LAC) has not been fully understood yet. Hence, this study aimed to determine the biological function of LINC00324 in LAC and to provide a novel diagnostic and therapeutic target for it. PATIENTS AND METHODS: The expression level of LINC00324 in 87 paired LAC tumor tissues and matched para-tumor tissues was detected using quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Cell counting kit-8 (CCK-8) assay was employed to analyze the cell proliferative ability, whereas flow cytometry was performed to detect cell apoptotic rate. Cell metastasis change was measured using wound-healing assay and transwell assay. Luciferase reporter gene assay and Western blotting analysis were utilized to investigate the underlying mechanism of LINC00324 in LAC. RESULTS: LINC00324 was highly expressed in LAC tissues compared with the para-tumor samples. Identically, the expression level of LINC00324 was significantly higher in LAC cell lines. The overexpression of LINC00324 promoted cell proliferation and inhibited cell apoptosis of LAC cells, while knockdown of LINC00324 presented the opposite effect. Up-regulation of LINC00324 accelerated cell migration and invasion, but down-regulation of LINC0324 decreased cell metastasis of LAC cells. Furthermore, miR-615-5p was found to be regulated by LINC00324 and inhibited AKT1 expression, indicating that LINC00324 promoted cell progression via affecting the miR-615-5p/AKT1 pathway. CONCLUSIONS: LINC00324 was significantly over-expressed in LAC tissues and cells. It promoted proliferation and metastasis but inhibited cell apoptosis of LAC cells via sponging miR-615-5p to promote AKT1 expression. Our results demonstrated LINC00324 as a novel diagnostic and therapeutic target for LAC.

A review of the genus Atrovirensis Kononenko, 2001 with description of four new species from China (Lepidoptera, Noctuidae: Xyleninae, Apameini).

The genus Atrovirensis Kononenko, 2001 is reviewed. Four new species (Atrovirensis parannamita sp. n., Atrovirensis furcatus sp. n., Atrovirensis sacculatus sp. n. and Atrovirensis miraculosus sp. n.) are described from China. A new combination Atrovirensis euplexina (Draudt, 1950), comb. n. [Valeria] is proposed. Two taxa of uncertain status (Atrovirensis sp. cf. parannamita and Atrovirensis sp. cf. furcatus) are included to the review. The updated checklist of the genus is presented. All taxa of the genus Atrovirensis are illustrated in colour with black and white photographs of their genitalia in 48 figures.

Structure and function of GABA(C) receptors: a comparison of native versus recombinant receptors.

In less than a decade our knowledge of the GABA(C) receptor, a new type of Cl(-)-permeable ionotropic GABA receptor, has greatly increased based on studies of both native and recombinant receptors. Careful comparison of properties of native and recombinant receptors has provided compelling evidence that GABA receptor rho-subunits are the major molecular components of GABA(C) receptors. Three distinct rho-subunits from various species have been cloned and the pattern of their expression in the retina, as well as in various brain regions, has been established. The pharmacological profile of GABA(C) receptors has been refined and more specific drugs have been developed. Molecular determinants that underlie functional properties of the receptors have been assigned to specific amino acid residues in rho-subunits. This information has helped determine the subunit composition of native receptors, as well as the molecular basis underlying subtle variations among GABA(C) receptors in different species. Finally, GABA(C) receptors play a unique functional role in retinal signal processing via three mechanisms: (1) slow activation; (2) segregation from other inhibitory receptors; and (3) contribution to multi-neuronal pathways.

Comparison of the actions of glycine and related amino acids on isolated third order neurons from the tiger salamander retina.

Whole cell voltage and current clamp recordings were obtained from third order neurons isolated from the salamander retina. Using cross desensitization, the structure-function relationship of short chain amino acids on the glycine receptor were examined. L-Serine, L-alanine, beta-alanine and taurine all cross desensitized with glycine, but did not show significant cross desensitization with GABA. This indicates that these amino acids act at the glycine receptor. The order of potency was glycine >> beta-alanine > taurine >> L-alanine > L-serine. TAG, a reputed selective taurine antagonist, was equally effective in blocking taurine and glycine currents. There is no evidence for distinct receptors for taurine. Amino acids with larger moieties at the alpha carbon, such as threonine and valine, produced inactive ligands. Placing a methyl group on the amine of glycine or esterification of the carboxyl group also greatly reduced activity. Based on these modifications of the glycine molecule, it appears that selectivity at the glycine receptor results in part from steric restrictions at all three sites in the glycine chain. The steric interference is most critical at the carboxyl and amino ends, and less limiting at the alpha carbon. Doses of L-serine that had only slight effects in voltage clamp experiments, nevertheless produced large effects in current clamp experiments. This indicates that several endogenous amino acids can have significant effects on membrane voltage, even when their shunting activity may be small. High concentrations of agonists produced desensitization in the voltage clamp records, but there was little evidence of desensitization in the current clamp experiments. These results indicate that several endogenous amino acids can activate the glycine receptor, but there is no evidence for a discrete receptor for taurine, beta-alanine, L-alanine or L-serine. Since all these endogenous amino acids have similar amino and acid terminals, reduction in potency results from steric interference around the alpha carbon. This graded potency may have functional significance in mediating inhibition.

Redox modulation of recombinant human GABA(A) receptors.

We previously reported that GABA-evoked currents of rat retinal ganglion cells were modulated by redox agents. In this study, we further characterized the effects of redox modulation on GABA receptors using recombinant human subunits in the Xenopus oocyte expression system with two-electrode voltage-clamp recording. GABA receptors composed of subunits alpha(1-3), beta(1-3), gamma(1), gamma(2S,) and rho(1) were expressed. The sulfhydryl reducing agent dithiothreitol reversibly potentiated the responses of various combinations of functional recombinant GABA(A) subunits, whether expressed as triplets (alpha(1)beta(1-3)gamma(1,2S)), pairs (alpha(1-3)beta(1-3); beta(1-3)gamma(1,2S)), or singly (beta(2)). These effects of dithiothreitol were rapidly reversible, and the oxidizing agent 5-5'-dithiobis-2-nitrobenzoic acid exerted the opposite effect. In contrast to these effects on GABA(A) receptors, dithiothreitol had no effect on the responses of homomeric GABA rho(1) (GABA(C)) receptors. The degree of dithiothreitol potentiation of GABA(A) receptor responses depended on subunit composition. Co-expression of gamma(2S) with alpha(1)beta(1-3) subunits resulted in markedly less dithiothreitol potentiation of GABA-evoked currents than that observed for alpha(1-3)beta(1-3) subunits in the absence of gamma(2S). None the less, the magnitude of dithiothreitol potentiation could be restored by using a combination of lower GABA concentrations (5-10 microM) and higher dithiothreitol concentrations (5-20mM). N,N,N', N'-tetrakis(2-pyridyl-methyl)ethylenediamine, a high-affinity Zn(2+) chelator, also potentiated GABA(A) receptor currents. However, the potentiation produced by 10mM dithiothreitol was larger than that produced by saturating concentrations of N,N,N', N'-tetrakis(2-pyridyl-methyl)ethylenediamine (100 microM), implying that at least part of the effect of dithiothreitol was due to redox modulation rather than Zn(2+) chelation. Dithiothreitol also potentiated the spontaneous current of homomeric GABA(A) receptors composed of beta subunits. Mutation of a single cysteine residue in the M3 domain, yielding homomeric beta(3)(C313A) receptors, abrogated dithiothreitol potentiation of the spontaneous current. In summary, this study further characterizes the modulatory effects of redox agents on recombinant GABA(A) receptors. The degree of redox modulation of GABA(A) receptors depended on subunit composition. In contrast to their effect on GABA(A) receptors, redox agents were not found to modulate GABA(C) receptors composed of homomeric rho(1) subunits. Using site-directed mutagenesis, a cysteine residue was located in the beta(3) subunit which may comprise one of the redox-active sites that underlies the modulation of heteromeric GABA(A) receptors by reducing and oxidizing agents.

The physiology of GABAB receptors in the vertebrate retina.

Writing a chapter on retinal GABAB receptors is premature, as evidenced by the paucity of citations more than two years old. Despite that, this area of retinal pharmacology has made significant strides and, although it is a story without an ending, it has had an exciting beginning. To date, the experiments indicate that horizontal cell feedback to cones is mediated, at least in part, by the GABAB receptor system which probably regulates a potassium conductance. In the inner retina, GABAB receptors are found on bipolar cells, amacrines, and ganglion cells. Here, the actions are a subtle regulation of channel conductance, but the effects are a dramatic reorganization of a fundamental coding property of the retina, namely the distinction between tonic and phasic responses to light. In both the distal and proximal retina, the GABAB receptor does not appear to work alone, but instead works in concert with the GABAA receptor. The full significance of these interactions has yet to be determined. Although the discovery of the GABAB receptor has led to the resolution of several retinal mysteries, the case is far from closed. At this juncture, what can be said is that the GABAB receptor represents a unique and ubiquitous system that reveals the power of regulating calcium and potassium conductances, as opposed to the more familiar properties of the glutamate/acetylcholine regulated cationic conductances or the GABAA/glycine controlled chloride channels.

Greater sensitivity of larger retinal ganglion cells to NMDA-mediated cell death.

Glutamate toxicity in retinal ganglion cells has well documented both in vitro and in vivo, and has been suggested to play a role in the neuronal loss in glaucoma. Of note, glaucoma selectively damages larger retinal ganglion cells first, and we therefore sought to explore whether glutamate-mediated cell death was likewise more pronounced in larger retinal ganglion cells. We now report that glutamate--which exerts its toxic effect on neurons predominantly through the N-methyl-D-aspartate (NMDA) subtype of glutamate receptor--is more toxic to larger retinal ganglion cells both in tissue culture and in the intact rat eye. Cells smaller than 10 microns were relatively unaffected by glutamate or NMDA. These agents are, however, markedly toxic to retinal ganglion cells larger than 10 microns. These observations indicate that glutamate-mediated loss is seen first in larger retinal ganglion cells, in a similar fashion to the pattern of loss seen in glaucoma.