Spatial distributions and environmentally-mediated factors of dimethylsulfoxide off the northern Antarctic Peninsula in summer.

Spatial distributions of dissolved and particulate dimethylsulfoxide (DMSOd and DMSOp) were investigated off the northern Antarctic Peninsula during the austral summer of 2018, an ecologically and climatically important region of the world. In the upper waters, DMSOd was concentrated in the ice-melt zone because DMSO functions physiologically as an intracellular osmolyte and cryoprotectant. DMSOd concentrations had a weak positive correlation with temperature but a negative correlation with nutrients. This highlighted the importance of temperature-dependent biological activities and photolysis in DMSOd production and the important role of the intracellular antioxidation system in phytoplankton cells. The decrease of average DMSOp:Chl-a ratios in upper waters from west to east, along with decreasing temperatures and increasing diatoms proportions in the phytoplankton, illustrates how seawater DMSO production capacities depend on ambient temperatures and the composition of phytoplankton assemblages. DMSOp were accumulated in deep waters through bio-debris accumulation and microbial activity.

Early effects of intravitreal anti-VEGF agents on cornea and visual acuity in patients with diabetic retinopathy.

PURPOSE: This study aimed to investigate the early effects of intravitreal anti-vascular endothelial growth factor (anti-VEGF) agents on the cornea and visual acuity in patients with diabetic retinopathy (DR). METHODS: This retrospective study enrolled patients who were administered conbercept or ranibizumab to treat DR. Fundus photograph, fluorescein angiograph, and optical coherence tomography were preoperatively performed. The patients were classified into two groups: nonproliferative DR (NPDR) and PDR. Best-corrected visual acuity (BCVA), specular microscopy, central corneal thickness (CCT), and intraocular pressure were obtained before injection and at 1 day and 7 days after injection. The effects of anti-VEGF agents on BCVA and CCT were compared between the groups receiving conbercept and ranibizumab and between NPDR and PDR eyes. RESULTS: A total 38 eyes (30 patients) were enrolled in this study. Twenty-one eyes received conbercept, and 17 eyes received ranibizumab. Twenty eyes were classified as NPDR and 18 eyes as PDR. No significant differences were found between the groups receiving conbercept and ranibizumab in the increase in BCVA nor in the increase of CCT at 1 day and 7 days after injection. As compared with NPDR eyes, PDR eyes demonstrated a significantly greater increase in CCT (-5.3 ± 3.7 vs. 6.5 ± 2.9 µm, P = 0.02 < 0.05) but not in BCVA (P = 0.33) at 1 day after injection. At 7 days after injection, no significant differences were found in the increase in BCVA nor in the increase of CCT between NPDR eyes and PDR eyes. CONCLUSION: Intravitreal administration of anti-VEGF agents could cause a small but significant greater increase in CCT in PDR than in NPDR eyes in the early period. In patients with DR, no significant difference was found between conbercept and ranibizumab in the early effects on the visual acuity nor in the cornea.

S/N-codoped carbon nanotubes and reduced graphene oxide aerogel based supercapacitors working in a wide temperature range.

Among many supercapacitor electrode materials, carbon materials are widely used due to their large specific surface area, good electrical conductivity and high economic efficiency. However, carbon-based supercapacitors face the challenges of low energy density and limited operating environment. This work reports a facile self-assembled method to prepare three-dimensional carbon nanotubes/reduced graphene oxide (CNTs/rGO) aerogel material, which was applied as both positive and negative electrodes in a symmetric superacapacitor. The fabricated supercapacitor exhibited prominent capacitive performance not only at room temperature, but also at extreme temperatures (-20 âˆ¼ 80 °C). The specific capacitances of the symmetric supercapacitors based on CNTs/rGO at a weight ratio of 2:5 respectively reached 107.8 and 128.2 F g-1 at 25 °C and 80 °C with KOH as the electrolyte, and 80.0 and 144.6 F g-1 at -20 °C and 60 °C with deep eutectic solvent as the electrolyte. Notably, the capacitance retention and coulombic efficiency of the assembled supercapacitors remained almost unchanged after 20,000 cycles of charge/discharge test over a wide temperature range. The work uncovered a possibility for the development of high-performance supercapacitors flexibly operated at extreme temperatures.

Euphorfinoids A and B, a pair of ent-atisane diterpenoid epimers from the roots of Euphorbia fischeriana, and their bioactivities.

Euphorfinoids A and B (1 and 2), a pair of ent-atisane diterpenoid epimers with a vicinal 2,3-diol moiety, together with four known analogues (3-6), were isolated from the roots of wild Euphorbia fischeriana. Their structures were elucidated by spectroscopic analysis, including extensive NMR, HR-ESIMS, NMR calculations, X-ray diffraction, and comparison with structurally related known analogues. Our bioassays have established that compound 1 displayed moderate anti-proliferative effects on Hcc1806 cell line with IC50 15.53 ± 0.21 µM, and compound 5 showed remarkable inhibitory effects against AChE with IC50 32.56 ± 2.74 µM by an in vitro screened experiment.

Most nonpathological eyes present a small area of hyperreflective Henle's fiber layer on pupil-centered optical coherence tomography.

PURPOSE: Henle's fiber layer (HFL) is hyporeflective and indistinct on pupil-centered optical coherence tomography (OCT). However, a small area of HFL is also found to be hyperreflective on pupil-centered OCT. This study characterized the hyperreflective HFL of healthy eyes on pupil-centered OCT and investigated the possible physiological and functional relationship of hyperreflective HFL. METHODS: Subjects with different degrees of ametropia underwent a complete ophthalmologic examination, including binocular function by synoptophore and Titmus test, ocular axial length, refractions, and pupil-centered OCT angiography coupled with OCT. The area of hyperreflective HFL was manually plotted and calculated using the Optovue AngioVue system technology. The possible ocular physiological and functional relationship with the area of hyperreflective HFL was investigated. RESULTS: A total of 111 subjects (222 eyes) without other ocular diseases were enrolled, of which 164 eyes (74%) presented hyperreflective HFL. The average area of hyperreflective HFL was 0.71 ± 0.07 mm2. The area of hyperreflective HFL was significantly related to spherical diopters (P = 0.032). The average binocular area of hyperreflective HFL was 1.38 ± 0.17 mm2. The binocular area of hyperreflective HFL was significantly related to the angle of superposition and far stereoacuity (P = 0.013 and 0.038, respectively). CONCLUSION: Most healthy eyes present a small area of hyperreflective HFL, which might be due to alternation of the orientation of some Henle fibers by ametropia during the development of visual function postpartum. The small area of hyperreflective HFL may serve as a marker in identifying the boundary of HFL on OCT.

Black Tea Reduces Diet-Induced Obesity in Mice via Modulation of Gut Microbiota and Gene Expression in Host Tissues.

Black tea was reported to alter the microbiome populations and metabolites in diet-induced obese mice and displays properties that prevent obesity, but the underlying mechanism of the preventative effect of black tea on high-fat diet (HFD) induced obesity has not been elucidated. Epigenetic studies are a useful tool for determining the relationship between obesity and environment. Here, we show that the water extract of black tea (Lapsang souchong, LS) reverses HFD-induced gut dysbiosis, alters the tissue gene expression, changes the level of a major epigenetic modification (DNA methylation), and prevents obesity in HFD feeding mice. The anti-obesity properties of black tea are due to alkaloids, which are the principal active components. Our data indicate that the anti-obesity benefits of black tea are transmitted via fecal transplantation, and the change of tissue gene expression and the preventative effects on HFD-induced obesity in mice of black tea are dependent on the gut microbiota. We further show that black tea could regulate the DNA methylation of imprinted genes in the spermatozoa of high-fat diet mice. Our results show a mechanistic link between black tea, changes in the gut microbiota, epigenetic processes, and tissue gene expression in the modulation of diet-induced metabolic dysfunction.

New Lanostane-Type Triterpenes with Anti-Inflammatory Activity from the Epidermis of Wolfiporia cocos.

A chemical study on the epidermis of cultivated edible mushroom Wolfiporia cocos resulted in the isolation and identification of 46 lanostane triterpenoids, containing 17 new compounds (1-17). An experimental determination of their anti-inflammatory activity showed that poricoic acid GM (39) most strongly inhibited NO production in LPS-induced RAW264.7 murine macrophages with an IC50 value at 9.73 µM. Furthermore, poricoic acid GM induced HO-1 protein expression and inhibited iNOS and COX2 protein expression as well as the release of PGE2, IL-1ß, IL-6, TNF-α, and reactive oxygen species (ROS) in LPS-induced RAW264.7 cells. Mechanistically, poricoic acid GM suppressed the phosphorylation of the IκBα protein, which prevented NF-κB from entering the nucleus to lose transcriptional activity and inhibited the dissociation of Keap1 from Nrf2, thereby activating Nrf2 into the nucleus to regulate antioxidant genes. Furthermore, the MAPK signaling pathway may play a significant role in poricoic acid GM-induced elimination of inflammation. This work further confirms that lanostane triterpenoids are key ingredients responsible for the anti-inflammatory properties of the edible medicinal mushroom W. cocos.

Euphorfistrines A-G, cytotoxic and AChE inhibiting triterpenoids from the roots of Euphorbia fischeriana.

Seven new triterpenoids including two cycloartanes (1-2), a lanostane (3), a tirucallane (4), a dammarane (5), an ursane (6), and an oleanane (7), along with nineteen known triterpenoids (8-26), have been obtained from the roots of Euphorbia fischeriana. Their structures were established by NMR, HRESIMS, single-crystal X-ray diffraction analysis, Mosher's method, NMR calculations, ECD analysis, and comparison with structurally related known analogues. Among them, compounds 1 and 8 were a pair of cycloartane-type triterpenoids epimers. Our bioassays have established that compounds 1-5 and 10 displayed moderate cytotoxic effects, and the structure-activity relationships of cycloartane-type triterpenoids (CTTs) were further examined. Notably, some triterpenoids displayed moderate inhibitory effects against AChE by an in vitro screened experiment. Triterpenoid 7 (Euphorfistrine G, ETG) displayed the potent inhibitory effect with IC50 = 2.45 and Ki = 2.30 µM (inhibition kinetic). And, in silico docking analyses have been performed to investigate the inhibitory mechanism of compound 7.

Panton-Valentine Leucocidin of Staphylococcus aureus Induces Oxidative Stress and Neurotransmitter Imbalance in a Retinal Explant Model.

Purpose: Endophthalmitis models have reported the virulent role of Panton-Valentine leucocidin (PVL) secreted by Staphylococcus aureus on the retina. PVL targets retinal ganglion cells (RGCs), expressing PVL membrane receptor C5aR. Interactions between PVL and retinal cells lead to glial activation, retinal inflammation, and apoptosis. In this study, we explored oxidative stress and retinal neurotransmitters in a rabbit retinal explant model incubated with PVL. Methods: Reactive oxygen species (ROS) production in RGCs has been assessed with fluorescent probes and immunohistochemistry. Nuclear magnetic resonance (NMR) spectroscopy quantified retinal concentrations of antioxidant molecules and neurotransmitters, and concentrations of neurotransmitters released in the culture medium. Quantifying the expression of some pro-inflammatory and anti-inflammatory factors was performed using RT-qPCR. Results: PVL induced a mitochondrial ROS production in RGCs after four hours' incubation with the toxin. Enzymatic sources of ROS, involving nicotinamide adenine dinucleotide phosphate-oxidase and xanthine oxidase, were also activated after four hours in PVL-treated retinal explants. Retinal antioxidants defenses, that is, glutathione, ascorbate and taurine, decreased after two hours' incubation with PVL. Glutamate retinal concentrations and glutamate release in the culture medium remained unaltered in PVL-treated retinas. GABA, glycine, and acetylcholine (Ach) retinal concentrations decreased after PVL treatment. Glycine release in the culture medium decreased, whereas Ach release increased after PVL treatment. Expression of proinflammatory and anti-inflammatory cytokines remained unchanged in PVL-treated explants. Conclusions: PVL activates oxidative pathways and alters neurotransmitter retinal concentrations and release, supporting the hypothesis that PVL could induce a neurogenic inflammation in the retina.

VISUAL IMPAIRMENT AND MACULAR VASCULAR REMODELING SECONDARY TO RETROGRADE MACULOPATHY IN RETINAL DETACHMENT TREATED WITH SILICON OIL TAMPONADE.

PURPOSE: To assess the frequency of macular cysts (MCs) in retinal detachment treated with silicone oil and evaluate their impact on visual acuity and macular vascularization using optical coherence tomography-angiography. METHODS: Forty-three eyes of 41 patients treated with silicone oil for retinal detachment were retrospectively studied. Best-corrected visual acuity and 6- × 6-mm optical coherence tomography-angiography examination at least 3 months after silicone oil removal were reviewed. In eyes with MCs, cyst area was measured on the en face optical coherence tomography-angiography image using ImageJ. Density of superficial capillary plexus and area of superficial foveal avascular zone were generated by the optical coherence tomography-angiography. Density of deep capillary plexus and deep foveal avascular zone area were measured using ImageJ. RESULTS: Twenty-five eyes (58%) presented with MCs. Cysts were exclusively located in the inner nuclear layer in 60% of cases. Mean best-corrected visual acuity in the MC group was lower than that of the non-MC group (P = 0.012). Macular cyst area negatively correlated with best-corrected visual acuity (P = 0.0201). Density of superficial capillary plexus was higher in the MC group (P < 0.0001), whereas area of superficial foveal avascular zone was lower (P < 0.0001). Macular cyst area negatively correlated with density of deep capillary plexus (P < 0.001). CONCLUSION: The incidence of INL-MCs after silicone oil removal is high. These are associated with impaired vision and macular vascular remodeling. We highlight their similarity with the "retrograde maculopathy" phenomenon.

Evolution of Dome-shaped Macula Is Due to Differential Elongation of the Eye Predominant in the Peri-dome Region.

PURPOSE: To determine the mechanism behind macular bulge height increase in eyes with dome-shaped macula (DSM). DESIGN: Retrospective, observational case series. METHODS: Eyes presenting with DSM followed up for a minimum of 1 year were examined using ocular biometry and spectral-domain optical coherence tomography at baseline and at end of follow-up. Axial length (AL), DSM bulge height, and central and peripheral choroidal thickness (nasal, temporal, superior, and inferior quadrants) were reported. Eyes were categorized into 2 groups for comparison: the "mini-DSM" group (DSM < 100 µm) and the "classic" DSM group (DSM > 100 µm). RESULTS: Fifty-eight eyes (33 patients) were studied: 32 (55%) were classic DSM and 26 (45%) mini-DSM. During the mean follow-up of 51.76 ± 36.01 months, mean AL increased from 26.99 ± 2.94 mm to 27.12 ± 3.09 mm (P = .010) and mean macular bulge height increased from 235.88 ± 282.47 µm to 262.34 ± 317.15 µm (P < .001). DSM height change was significantly higher than AL change (P < .001). Mean peripheral choroidal thickness significantly decreased nasally (P = .008), temporally (P = .026), and inferiorly (P < .001). Mini-DSM eyes exhibited shorter AL (26.17 vs 27.66 mm; P = .027), greater visual acuity (0.169 vs 0.437 logMAR; P = .002), and fewer macular complications compared to classic DSM eyes. CONCLUSIONS: Macular bulge increase in DSM is associated with eye elongation and overall thinning of the peripheral choroid. DSM might result from differential elongation of the eye predominant in the peri-dome region. Mini-DSM (ie, inferior to 100 µm) are characterized by slower evolution, better visual prognosis, and fewer complications compared to "classic" DSM.

Serous Retinal Detachment in Dome-Shaped Macula Is Associated with Greater Central Choroidal Blood Flow Measured by Optical Coherence Tomography Angiography.

PURPOSE: Dome-shaped macula (DSM) is characterized by an inward bulge in the macula, often associated with a myopic staphyloma. One complication of DSM is particularly studied: foveolar serous retinal detachment (SRD). This study analyzed the variations of optical coherence tomography angiography (OCT-A) decorrelation signal in cases of DSM with and without SRD. METHODS: This was a retrospective study including twenty height eyes presenting with DSM. OCT-A scans were recorded, and the intensity of the choroidal decorrelation signal was quantified to analyze choroidal blood flow (CBF) in central, temporal, and nasal macular areas. The size of retinal pigment epithelium (RPE) atrophy was evaluated. RESULTS: CBF in the central area was significantly greater in the SRD group than in the no-SRD group (7.00 × 105 vs. 2.58 × 105) (p = 0.0049). CBF appeared decreased in the subfoveal area compared with the periphery for patients without SRD (p = 0.0107). The size of RPE atrophy was 0.762 optic disc area ±0.87. RPE atrophy correlated very significantly with CBF (p = 0.0012). CONCLUSION: A greater retrofoveolar CBF intensity is associated with the presence of SRD. These changes could reflect variations of CBF, and may represent a potential explanation for the pathogenesis of SRD in DSM.

Panton-Valentine Leucocidin Proves Direct Neuronal Targeting and Its Early Neuronal and Glial Impacts a Rabbit Retinal Explant Model.

: Panton-Valentine leukocidin (PVL) retinal intoxication induces glial activation and inflammatory response via the interaction with retinal neurons. In this study, rabbit retinal explant was used as a model to study neuronal and glial consequences of PVL intoxication. Retinal explants were treated with different concentrations of PVL. PVL location and neuronal and glial changes were examined using immunohistochemistry. Some inflammatory factors were quantified using RT-qPCR at 4 and 8 h. These results were compared with those of control explants. PVL co-localized rapidly with retinal ganglion cells and with horizontal cells. PVL induced Müller and microglial cell activation. Retinal structure was altered and some amacrine and microglial cells underwent apoptosis. Glial activation and cell apoptosis increased in a PVL concentration- and time-dependent manner. IL-6 and IL-8 expression increased in PVL-treated explants but less than in control explants, which may indicate that other factors were responsible for glial activation and retinal apoptosis. On retinal explants, PVL co-localized with neuronal cells and induced glial activation together with microglial apoptosis, which confirms previous results observed in in vivo model. Rabbit retinal explant seems to be suitable model to further study the process of PVL leading to glial activation and retinal cells apoptosis.

Caudatan A, an undescribed human kidney-type glutaminase inhibitor with tetracyclic flavan from Ohwia caudata.

Human kidney-type glutaminase (KGA) is an important target that is often over expressed in many cancer cells but very few effective inhibitors of this enzyme have yet reached clinical trials. Caudatan A and caudatan B, two undescribed tetracyclic flavans with an unusual ether bond between the C-4 and C-2' were isolated from the roots of Ohwia caudata (Thunb.) H.Ohashi. Caudatan A exhibited stronger inhibitory activity and caudatan B showed moderate effect from the results of inhibitory activities evaluations on KGA. The molecular docking and primary structure-activity relationship analysis revealed that the less steric hindrance at ring A was necessary to the effect. Therefore, combined its better solubility than that of bis-2-(5-phenylacetimido-1,2,4-thiadiazol-2-yl)ethyl sulfide (BPTES), caudatan A might be the potential candidate as the inhibitor of KGA for further studies.

Panton-Valentine Leukocidin Colocalizes with Retinal Ganglion and Amacrine Cells and Activates Glial Reactions and Microglial Apoptosis.

Experimental models have established Panton-Valentine leukocidin (PVL) as a potential critical virulence factor during Staphylococcus aureus endophthalmitis. In the present study, we aimed to identify retinal cell targets for PVL and to analyze early retinal changes during infection. After the intravitreous injection of PVL, adult rabbits were euthanized at different time points (30 min, 1, 2, 4 and 8 h). PVL location in the retina, expression of its binding receptor C5a receptor (C5aR), and changes in Müller and microglial cells were analyzed using immunohistochemistry, Western blotting and RT-qPCR. In this model of PVL eye intoxication, only retinal ganglion cells (RGCs) expressed C5aR, and PVL was identified on the surface of two kinds of retinal neural cells. PVL-linked fluorescence increased in RGCs over time, reaching 98% of all RGCs 2 h after PVL injection. However, displaced amacrine cells (DACs) transiently colocalized with PVL. Müller and microglial cells were increasingly activated after injection over time. IL-6 expression in retina increased and some microglial cells underwent apoptosis 4 h and 8 h after PVL infection, probably because of abnormal nitrotyrosine production in the retina.

A mitochondria-targeted ratiometric fluorescent probe for hypochlorite and its applications in bioimaging.

A novel ratiometric probe (RCP) for -OCl was developed based on the fluorescence resonance energy transfer (FRET) platform. The probe was constructed by integrating the coumarin moiety (FRET donor) with the rhodamine moiety (FRET acceptor). Upon treatment with -OCl, the coumarin emission at 483 nm decreased and the rhodamine emission at 570 nm increased, enabling the probe to provide accurate detection of -OCl (in the concentration range of 0-50 µM). The probe exhibited brilliant selectivity and sensitivity, rapid response and low cytotoxicity. More importantly, the introduction of the quaternized pyridine moiety can not only manage to increase the solubility, but also achieve mitochondria-targeting. The probe was applied successfully to imaging endogenous -OCl in mitochondria, highlighting its potential applications in bioanalysis.

Anti-gout nor-oleanane triterpenoids from the leaves of Stauntonia brachyanthera.

With the aim of finding more potential anti-gout compounds from natural resources, a phytochemical study on the leaves of Stauntonia brachyanthera was carried out, which led to the isolation of 11 nor-oleanane triterpenoids, including 4 new ones. Their structures were determined by the comprehensive 1D, 2D NMR, HRMS, and HPLC analysis after acid hydrolysis. Brachyantheraoside B4 (3) and 3-O-α-l-rhamnopyranosyl-(1→2)-α-l-arabinopyranosyl-30-norolean-12,20(29)-dien-28-oic acid (8) exhibited significant inhibitory activities on xanthine oxidase with IC50 values of 0.20 and 18.5µM, respectively. Brachyantheraoside C2 (2) also showed moderate effects on XO. A primary structure-activity relationship was also summarized, which revealed the anti-gout abilities of three nor-oleanane triterpenoids and their potential possibilities as the candidate compounds for the treatment of gout. The discovery of nor-oleanane triterpenoids also widens people's idea for the study of anti-gout agents and promotes the comprehensive development of S. brachyanthera.

Investigation of the efficiency of intrastromal ring segments with cross-linking using different sequence and timing for keratoconus.

AIM: To evaluate and compare the efficacy and stability of intrastromal corneal ring segment (ICRs) implantation with cross-linking (CXL) using different sequence and timing. METHODS: In this single retrospective study, 86 keratoconic eyes subjected the ICRs implantation. We analyzed only 41 eyes that had complete follow-ups. They were divided into three groups: ICRs implantation was applied only (group normal), ICRs first followed by CXL immediately (group CXL-S), CXL first followed by ICRs long after (group CXL-B). The visual acuity, refractive results, keratometry were compared preoperatively and 1y postoperatively. Their differences among the three groups were also analyzed. RESULTS: Group normal comprised 25 eyes, group CXL-S 8 eyes, and group CXL-B 8 eyes. There were improvements in the mean uncorrected distance visual acuity (UDVA) and the mean corrected distance visual acuity (CDVA) compared preoperatively and 1y postoperatively {UDVA: 0.31 (P=0.030) logarithmic minimum angle of resolution [logMAR] group normal, 0.4 (P=0.020) group CXL-S, 0.45 (P=0.001) group CXL-B; CDVA: 0.21 logMAR (P=0.013) group normal, 0.30 (P=0.036) group CXL-S; 0.26 (P=0.000) group CXL-B}. The refractive and topographic outcomes also showed improvements. In terms of comparisons among the three groups, all the P values were above 0.05, showing no significant difference. But only group CXL-B had improvement in UDVA and CDVA for all the patients. CONCLUSION: With safety and good visual outcomes, ICRs implantation is a viable alternative for keratoconus. No significant difference was found among these three groups.