Optimal transcorneal electrical stimulation parameters for preserving photoreceptors in a mouse model of retinitis pigmentosa.

JOURNAL/nrgr/04.03/01300535-202419110-00034/figure1/v/2024-03-08T184507Z/r/image-tiff Retinitis pigmentosa is a hereditary retinal disease that affects rod and cone photoreceptors, leading to progressive photoreceptor loss. Previous research supports the beneficial effect of electrical stimulation on photoreceptor survival. This study aims to identify the most effective electrical stimulation parameters and functional advantages of transcorneal electrical stimulation (tcES) in mice affected by inherited retinal degeneration. Additionally, the study seeked to analyze the electric field that reaches the retina in both eyes in mice and post-mortem humans. In this study, we recorded waveforms and voltages directed to the retina during transcorneal electrical stimulation in C57BL/6J mice using an intraocular needle probe with rectangular, sine, and ramp waveforms. To investigate the functional effects of electrical stimulation on photoreceptors, we used human retinal explant cultures and rhodopsin knockout (Rho-/-) mice, demonstrating progressive photoreceptor degeneration with age. Human retinal explants isolated from the donors' eyes were then subjected to electrical stimulation and cultured for 48 hours to simulate the neurodegenerative environment in vitro. Photoreceptor density was evaluated by rhodopsin immunolabeling. In vivo Rho-/- mice were subjected to two 5-day series of daily transcorneal electrical stimulation using rectangular and ramp waveforms. Retinal function and visual perception of mice were evaluated by electroretinography and optomotor response (OMR), respectively. Immunolabeling was used to assess the morphological and biochemical changes of the photoreceptor and bipolar cells in mouse retinas. Oscilloscope recordings indicated effective delivery of rectangular, sine, and ramp waveforms to the retina by transcorneal electrical stimulation, of which the ramp waveform required the lowest voltage. Evaluation of the total conductive resistance of the post-mortem human compared to the mouse eyes indicated higher cornea-to-retina resistance in human eyes. The temperature recordings during and after electrical stimulation indicated no significant temperature change in vivo and only a subtle temperature increase in vitro (~0.5-1.5°C). Electrical stimulation increased photoreceptor survival in human retinal explant cultures, particularly at the ramp waveform. Transcorneal electrical stimulation (rectangular + ramp) waveforms significantly improved the survival and function of S and M-cones and enhanced visual acuity based on the optomotor response results. Histology and immunolabeling demonstrated increased photoreceptor survival, improved outer nuclear layer thickness, and increased bipolar cell sprouting in Rho-/- mice. These results indicate that transcorneal electrical stimulation effectively delivers the electrical field to the retina, improves photoreceptor survival in both human and mouse retinas, and increases visual function in Rho-/- mice. Combined rectangular and ramp waveform stimulation can promote photoreceptor survival in a minimally invasive fashion.

Suppressing DNMT3a Alleviates the Intrinsic Epigenetic Barrier for Optic Nerve Regeneration and Restores Vision in Adult Mice.

The limited regenerative potential of the optic nerve in adult mammals presents a major challenge for restoring vision after optic nerve trauma or disease. The mechanisms of this regenerative failure are not fully understood1,2. Here, through small-molecule and genetic screening for epigenetic modulators3, we identify DNA methyltransferase 3a (DNMT3a) as a potent inhibitor of axon regeneration in mouse and human retinal explants. Selective suppression of DNMT3a in retinal ganglion cells (RGCs) by gene targeting or delivery of shRNA leads to robust, full-length regeneration of RGC axons through the optic nerve and restoration of vision in adult mice after nerve crush injury. Genome-wide bisulfite and transcriptome profiling in combination with single nucleus RNA-sequencing of RGCs revealed selective DNA demethylation and reactivation of genetic programs supporting neuronal survival and axonal growth/regeneration by DNMT3a deficiency. This was accompanied by the suppression of gene networks associated with apoptosis and inflammation. Our results identify DNMT3a as the central orchestrator of an RGC-intrinsic mechanism that limits optic nerve regeneration. Suppressing DNMT3a expression in RGCs unlocks the epigenetic switch for optic nerve regeneration and presents a promising therapeutic avenue for effectively reversing vision loss resulted from optic nerve trauma or diseases.

IGFBPL1 is a master driver of microglia homeostasis and resolution of neuroinflammation in glaucoma and brain tauopathy.

Microglia shift toward an inflammatory phenotype during aging that is thought to exacerbate age-related neurodegeneration. The molecular and cellular signals that resolve neuroinflammation post-injury are largely undefined. Here, we exploit systems genetics methods based on the extended BXD murine reference family and identify IGFBPL1 as an upstream cis-regulator of microglia-specific genes to switch off inflammation. IGFBPL1 is expressed by mouse and human microglia, and higher levels of its expression resolve lipopolysaccharide-induced neuroinflammation by resetting the transcriptome signature back to a homeostatic state via IGF1R signaling. Conversely, IGFBPL1 deficiency or selective deletion of IGF1R in microglia shifts these cells to an inflammatory landscape and induces early manifestation of brain tauopathy and retinal neurodegeneration. Therapeutic administration of IGFBPL1 drives pro-homeostatic microglia and prevents glaucomatous neurodegeneration and vision loss in mice. These results identify IGFBPL1 as a master driver of the counter-inflammatory microglial modulator that presents an endogenous resolution of neuroinflammation to prevent neurodegeneration in eye and brain.

Electrical stimulation alters DNA methylation and promotes neurite outgrowth.

Electrical stimulation (ES) influences neural regeneration and functionality. We here investigate whether ES regulates DNA demethylation, a critical epigenetic event known to influence nerve regeneration. Retinal ganglion cells (RGCs) have long served as a standard model for central nervous system neurons, whose growth and disease development are reportedly affected by DNA methylation. The current study focuses on the ability of ES to rescue RGCs and preserve vision by modulating DNA demethylation. To evaluate DNA demethylation pattern during development, RGCs from mice at different stages of development, were analyzed using qPCR for ten-eleven translocation (TETs) and immunostained for 5 hydroxymethylcytosine (5hmc) and 5 methylcytosine (5mc). To understand the effect of ES on neurite outgrowth and DNA demethylation, cells were subjected to ES at 75 µAmp biphasic ramp for 20 min and cultured for 5 days. ES increased TETs mediated neurite outgrowth, DNA demethylation, TET1 and growth associated protein 43 levels significantly. Immunostaining of PC12 cells following ES for histone 3 lysine 9 trimethylation showed cells attained an antiheterochromatin configuration. Cultured mouse and human retinal explants stained with ß-III tubulin exhibited increased neurite growth following ES. Finally, mice subjected to optic nerve crush injury followed by ES exhibited improved RGCs function and phenotype as validated using electroretinogram and immunohistochemistry. Our results point to a possible therapeutic regulation of DNA demethylation by ES in neurons.

The Role of Gut Microbiota in Glaucoma Progression and Other Retinal Diseases.

As a rapidly growing field, microbiota research offers novel approaches to promoting ocular health and treating major retinal diseases, such as glaucoma. Gut microbiota changes throughout life; however, certain patterns of population changes have been increasingly associated with specific diseases. It has been well established that a disrupted microbiome contributes to central nervous system diseases, including Alzheimer disease, Parkinson disease, multiple sclerosis, and glioma, suggesting a prominent role of microbiome in neurodegenerative diseases. This review summarizes the progress in identifying significant changes in the microbial composition of patients with glaucoma by compiling studies on the association between microbiota and disease progression. Of interest is the relationship between increased Firmicutes/Bacteroidetes ratio in patients with primary open-angle glaucoma, increased taurocholic acid, decreased glutathione, and a reduction in retinal ganglion cell survival. Connecting these microbes to specific metabolites sheds light on the pathogenic mechanism and novel treatment strategies. In summary, the current review synthesizes the findings of several studies investigating the effects of shifting bacterial population in retinal diseases, particularly glaucoma, with the aim to identify the current direction of treatment and help direct future endeavors.

Association between HSP-Specific T-Cell Counts and Retinal Nerve Fiber Layer Thickness in Patients with Primary Open-Angle Glaucoma.

Objective: Previous laboratory reports implicate heat shock protein (HSP)-specific T-cell responses in glaucoma pathogenesis; here, we aimed to provide direct clinical evidence by correlating systemic HSP-specific T-cell levels with glaucoma severity in patients with primary open-angle glaucoma (POAG). Design: Cross-sectional case-control study. Subjects: Thirty-two adult patients with POAG and 38 controls underwent blood draw and optic nerve imaging. Methods: Peripheral blood monocytes (PBMC) were stimulated in culture with HSP27, α-crystallin, a member of the small HSP family, or HSP60. Both interferon-γ (IFN-γ)+ CD4+ T helper type 1 cells (Th1) and transforming growth factor-ß1 (TGF-ß1)+ CD4+ regulatory T cells (Treg) were quantified by flow cytometry and presented as a percentage of total PBMC counts. Relevant cytokines were measured using enzyme-linked immunosorbent assays. Retinal nerve fiber layer thickness (RNFLT) was measured with OCT. Pearson's correlation (r) was used to assess correlations. Main Outcome Measures: Correlations of HSP-specific T-cell counts, and serum levels of corresponding cytokine levels with RNFLT. Results: Patients with POAG (visual field mean deviation, -4.7 ± 4.0 dB) and controls were similar in age, gender, and body mass index. Moreover, 46.9% of POAG and 60.0% of control subjects had prior cataract surgery (P = 0.48). Although no significant difference in total nonstimulated CD4+ Th1 or Treg cells was detected, patients with POAG exhibited significantly higher frequencies of Th1 cells specific for HSP27, α-crystallin, or HSP60 than controls (7.3 ± 7.9% vs. 2.6 ± 2.0%, P = 0.004; 5.8 ± 2.7% vs. 1.8 ± 1.3%, P < 0.001; 13.2 ± 13.3 vs. 4.3 ± 5.2, P = 0.01; respectively), but similar Treg specific for the same HSPs compared with controls (P ≥ 0.10 for all). Concordantly, the serum levels of IFN-γ were higher in POAG than in controls (36.2 ± 12.1 pg/ml vs. 10.0 ± 4.3 pg/ml; P < 0.001), but TGF-ß1 levels did not differ. Average RNFLT of both eyes negatively correlated with HSP27- and α-crystallin-specific Th1 cell counts, and IFN-γ levels in all subjects after adjusting for age (partial correlation coefficient r = -0.31, P = 0.03; r = -0.52, p = 0.002; r = -0.72, P < 0.001, respectively). Conclusions: Higher levels of HSP-specific Th1 cells are associated with thinner RNFLT in patients with POAG and control subjects. The significant inverse relationship between systemic HSP-specific Th1 cell count and RNFLT supports the role of these T cells in glaucomatous neurodegeneration. Financial Disclosures: Proprietary or commercial disclosure may be found after the references.

Berberine blocks inflammasome activation and alleviates diabetic cardiomyopathy via the miR­18a­3p/Gsdmd pathway.

Diabetic cardiomyopathy (DCM) is a cardiovascular disease which has been reported as a major cause of mortality worldwide for several years. Berberine (BBR) is a natural compound extracted from a Chinese herb, with a clinically reported anti­DCM effect; however, its molecular mechanisms have not yet been fully elucidated. The present study indicated that BBR markedly alleviated DCM by inhibiting IL­1ß secretion and the expression of gasdermin D (Gsdmd) at the post­transcriptional level. Considering the importance of microRNAs (miRNAs/miRs) in the regulation of the post­transcriptional process of specific genes, the ability of BBR to upregulate the expression levels of miR­18a­3p by activating its promoter (­1,000/­500) was examined. Notably, miR­18a­3p targeted Gsdmd and abated pyroptosis in high glucose­treated H9C2 cells. Moreover, miR­18a­3p overexpression inhibited Gsdmd expression and improved biomarkers of cardiac function in a rat model of DCM. On the whole, the findings of the present study indicate that BBR alleviates DCM by inhibiting miR­18a­3p­mediated Gsdmd activation; thus, BBR may be considered a potential therapeutic agent for the treatment of DCM.

Prevalence and risk factors of covert hepatic encephalopathy in cirrhotic patients: A multicenter study in China.

OBJECTIVE: We aimed to investigate the prevalence of covert hepatic encephalopathy (CHE) in cirrhotic patients in China and its risk factors. METHODS: A multicenter prospective observational study was conducted from January 2021 to March 2022 at 16 medical centers across China to investigate the risk factors of CHE and establish a prediction model for CHE episodes. RESULTS: A total of 528 patients were enrolled in the study. Based on both the psychometric hepatic encephalopathy score and Stroop test results, the prevalence of CHE was 50.4% (266/528), and the consistency between these two tests was 68.9%. Multivariate analysis showed that age (odds ratio [OR] 1.043, 95% confidence interval [CI] 1.022-1.063, P < 0.001), duration of education (OR 0.891, 95% CI 0.832-0.954, P = 0.001), comorbidities of cardiovascular diseases, hypertension, cerebral apoplexy or diabetes mellitus (OR 2.072, 95% CI 1.370-3.133, P < 0.001), Child-Pugh score (OR 1.142, 95% CI 1.029-1.465, P = 0.025), and blood urea nitrogen concentration (OR 1.126, 95% CI 1.038-1.221, P = 0.004) were associated with CHE episodes. According to the Chronic Liver Disease Questionnaire, CHE patients had lower scores for abdominal symptoms and systemic symptoms (P < 0.001), indicating a poor health-related quality of life. Based on a stepwise Cox regression hazard model, we established a nomogram for determining the probabilities of CHE episodes, and the area under the receiver operating characteristic curve was 0.733 (95% CI 0.679-0.788) and 0.713 (95% CI 0.628-0.797) in the training and validation cohorts. CONCLUSIONS: CHE is a common complication of cirrhosis in China. Large-scale studies with long-term follow-up are needed to determine the natural history of Chinese CHE patients.

Aberrant RNA m6A modification in gastrointestinal malignancies: versatile regulators of cancer hallmarks and novel therapeutic opportunities.

Gastrointestinal (GI) cancer is one of the most common malignancies, and a leading cause of cancer-related death worldwide. However, molecular targeted therapies are still lacking, leading to poor treatment efficacies. As an important layer of epigenetic regulation, RNA N6-Methyladenosine (m6A) modification is recently linked to various biological hallmarks of cancer by orchestrating RNA metabolism, including RNA splicing, export, translation, and decay, which is partially involved in a novel biological process termed phase separation. Through these regulatory mechanisms, m6A dictates gene expression in a dynamic and reversible manner and may play oncogenic, tumor suppressive or context-dependent roles in GI tumorigenesis. Therefore, regulators and effectors of m6A, as well as their modified substrates, represent a novel class of molecular targets for cancer treatments. In this review, we comprehensively summarize recent advances in this field and highlight research findings that documented key roles of RNA m6A modification in governing hallmarks of GI cancers. From a historical perspective, milestone findings in m6A machinery are integrated with a timeline of developing m6A targeting compounds. These available chemical compounds, as well as other approaches that target core components of the RNA m6A pathway hold promises for clinical translational to treat human GI cancers. Further investigation on several outstanding issues, e.g. how oncogenic insults may disrupt m6A homeostasis, and how m6A modification impacts on the tumor microenvironment, may dissect novel mechanisms underlying human tumorigenesis and identifies next-generation anti-cancer therapeutics. In this review, we discuss advances in our understanding of m6A RNA modification since its discovery in the 1970s to the latest progress in defining its potential clinic relevance. We summarize the molecular basis and roles of m6A regulators in the hallmarks of GI cancer and discuss their context-dependent functions. Furthermore, the identification and characterization of inhibitors or activators of m6A regulators and their potential anti-cancer effects are discussed. With the rapid growth in this field there is significant potential for developing m6A targeted therapy in GI cancers.

Description of a Nonhuman Primate Model of Retinal Ischemia/Reperfusion Injury.

Purpose: To establish an inducible model of retinal ischemia/reperfusion injury (RI/RI) in nonhuman primates (NHPs) to improve our understanding of the disease conditions and evaluate treatment interventions in humans. Methods: We cannulated the right eye of rhesus macaques with a needle attached to a normal saline solution reservoir at up to 1.9 m above the eye level that resulted in high intraocular pressure of over 100 mm Hg for 90 minutes. Retinal morphology and function were monitored before and after RI/RI over two months by fundus photography, optical coherence tomography, electroretinography, and visual evoked potential. Terminal experiments involved immunostaining for retinal ganglion cell marker Brn3a, glial fibrillary acidic protein, and quantitative polymerase chain reaction to assess retinal inflammatory biomarkers. Results: We observed significant and progressive declines in retinal and retinal nerve fiber layer thickness in the affected eye after RI/RI. We noted significant reductions in amplitudes of electroretinography a-wave, b-wave, and visual evoked potential N2-P2, with minimal recovery at 63 days after injury. Terminal experiments conducted two months after injury revealed ∼73% loss of retinal ganglion cells and a fivefold increase in glial fibrillary acid protein immunofluorescence intensity compared to the uninjured eyes. We observed marked increases in tumor necrosis factor-alpha, interferon-gamma, interleukin-1beta, and inducible nitric oxide synthase in the injured retinas. Conclusions: The results demonstrated that the pathophysiology observed in the NHP model of RI/RI is comparable to that of human diseases and suggest that the NHP model may serve as a valuable tool for translating interventions into viable treatment approaches. Translational Relevance: The model serves as a useful platform to study potential interventions and treatments for RI/RI or blinding retinal diseases.

Transcorneal but not transpalpebral electrical stimulation disrupts mucin homeostasis of the ocular surface.

PURPOSE: Transcorneal electrical stimulation (TcES) is increasingly applied as a therapy for preserving and improving vision in retinal neurodegenerative and ischemic disorders. However, a common complaint about TcES is its induction of eye pain and dryness in the clinic, while the mechanisms remain unknown. METHOD: TcES or transpalpebral ES (TpES) was conducted in C57BL6j mice for 14 days. The contralateral eyes were used as non-stimulated controls. Levels of intracellular [Ca2+] ([Ca2+]i) were assessed by Fura-2AM. The conductance resistances of the eye under various ES conditions were measured in vivo by an oscilloscope. RESULTS: Although TcES did not affect tear production, it significantly induced damage to the ocular surface, as revealed by corneal fluorescein staining that was accompanied by significantly decreased mucin (MUC) 4 expression compared to the control. Similar effects of ES were detected in cultured primary corneal epithelium cells, showing decreased MUC4 and ZO-1 levels after the ES in vitro. In addition, TcES decreased secretion of MUC5AC from the conjunctiva in vivo, which was also corroborated in goblet cell cultures, where ES significantly attenuated carbachol-induced [Ca2+]i increase. In contrast to TcES, transpalpebral ES (TpES) did not induce corneal fluorescein staining while significantly increasing tear production. Importantly, the conductive resistance from orbital skin to the TpES was significantly smaller than that from the cornea to the retina in TcES. CONCLUSION: TcES, but not TpES, induces corneal epithelial damage in mice by disrupting mucin homeostasis. TpES thus may represent a safer and more effective ES approach for treating retinal neurodegeneration clinically.

Prediction of Esophageal Stricture after Endoscopic Submucosal Dissection in Patients with Early Esophageal Cancer.

BACKGROUND: Endoscopic submucosal dissection (ESD) treatment of early esophageal cancer is effective and safe. It is currently the first-line treatment for early esophageal cancer. However, a common side effect is the development of esophageal strictures after ESD. This study was designed to identify the risk factors for esophageal stricture development and to predict its occurrence after ESD. METHODS: In this retrospective study, 150 consecutive patients with early esophageal cancer treated with ESD at Daping Hospital, Chongqing, were enrolled between January 2016 and December 2020. Data on patient demographics, esophageal tumor characteristics, procedure-related factors, and postoperative situations were collected. We identified independent risk factors of esophageal stricture formation using univariate analysis and multivariate logistic regression. The predictive probability was obtained after multivariate logistic analysis. In addition, patients were divided into six groups based on these risk factors and the rate of esophageal stricture in each group was analyzed. RESULTS: The postoperative esophageal stricture rate was 14% (21/150). Tumor location (OR = 5.655, 95% CI: 1.245-25.691, P = 0.025) and circumferential resection range (OR = 16.113, 95% CI: 4.294-60.466, P < 0.001) are independent risk factors for the development of esophageal strictures. According to predictive probability analysis and the rates of stricture in six groups, we developed a possible flow chart to predict stricture formation. CONCLUSIONS: Tumor location and circumferential resection range are reliable risk factors to predict the occurrence of esophageal strictures. Our prediction flow chart suggests that tumors with a circumferential resection range of 1/2-3/4 and located above the upper thoracic segment or a circumferential resection range of > 3/4 have a high risk of postoperative stricture. Thus, timely and effective preventive measures should be taken in these patients following ESD.

Direct modulation of microglial function by electrical field.

Non-invasive electric stimulation (ES) employing a low-intensity electric current presents a potential therapeutic modality that can be applied for treating retinal and brain neurodegenerative disorders. As neurons are known to respond directly to ES, the effects of ES on glia cells are poorly studied. A key question is if ES directly mediates microglial function or modulates their activity merely via neuron-glial signaling. Here, we demonstrated the direct effects of ES on microglia in the BV-2 cells-an immortalized murine microglial cell line. The low current ES in a biphasic ramp waveform, but not that of rectangular or sine waveforms, significantly suppressed the motility and migration of BV-2 microglia in culture without causing cytotoxicity. This was associated with diminished cytoskeleton reorganization and microvilli formation in BV-2 cultures, as demonstrated by immunostaining of cytoskeletal proteins, F-actin and ß-tubulin, and scanning electron microscopy. Moreover, ES of a ramp waveform reduced microglial phagocytosis of fluorescent zymosan particles and suppressed lipopolysaccharide (LPS)-induced pro-inflammatory cytokine expression in BV-2 cells as shown by Proteome Profiler Mouse Cytokine Array. The results of quantitative PCR and immunostaining for cyclooxygenase-2, Interleukin 6, and Tumor Necrosis Factor-α corroborated the direct suppression of LPS-induced microglial responses by a ramp ES. Transcriptome profiling further demonstrated that ramp ES effectively suppressed nearly half of the LPS-induced genes, primarily relating to cellular motility, energy metabolism, and calcium signaling. Our results reveal a direct modulatory effect of ES on previously thought electrically "non-responsive" microglia and suggest a new avenue of employing ES for anti-inflammatory therapy.

Epigenetic Regulation of Optic Nerve Development, Protection, and Repair.

Epigenetic factors are known to influence tissue development, functionality, and their response to pathophysiology. This review will focus on different types of epigenetic regulators and their associated molecular apparatus that affect the optic nerve. A comprehensive understanding of epigenetic regulation in optic nerve development and homeostasis will help us unravel novel molecular pathways and pave the way to design blueprints for effective therapeutics to address optic nerve protection, repair, and regeneration.

Apolipoprotein E4 impairs the response of neurodegenerative retinal microglia and prevents neuronal loss in glaucoma.

The apolipoprotein E4 (APOE4) allele is associated with an increased risk of Alzheimer disease and a decreased risk of glaucoma, but the underlying mechanisms remain poorly understood. Here, we found that in two mouse glaucoma models, microglia transitioned to a neurodegenerative phenotype characterized by upregulation of Apoe and Lgals3 (Galectin-3), which were also upregulated in human glaucomatous retinas. Mice with targeted deletion of Apoe in microglia or carrying the human APOE4 allele were protected from retinal ganglion cell (RGC) loss, despite elevated intraocular pressure (IOP). Similarly to Apoe-/- retinal microglia, APOE4-expressing microglia did not upregulate neurodegeneration-associated genes, including Lgals3, following IOP elevation. Genetic and pharmacologic targeting of Galectin-3 ameliorated RGC degeneration, and Galectin-3 expression was attenuated in human APOE4 glaucoma samples. These results demonstrate that impaired activation of APOE4 microglia is protective in glaucoma and that the APOE-Galectin-3 signaling can be targeted to treat this blinding disease.

Study on Bulk Texture and Mechanical Properties of As-Extruded Wide Mg-Al-Zn Alloy Sheets with Different Al Addition.

The wide Mg alloy sheets produced by hot extrusion usually can easily form an inhomogeneous texture, resulting in anisotropic mechanical properties and poor formability. However, few studies have been carried out on the bulk texture investigation at different areas of as-extruded Mg alloy sheets, especially the Mg alloys with different alloying elements. In this work, the effect of Al on the bulk texture and mechanical properties at different areas for three wide Mg-Al-Zn alloy sheets with different Al contents (Mg-3Al-0.5Zn, Mg-8Al-0.5Zn and Mg-9Al-0.5Zn) are mainly investigated by neutron diffraction. The results showed that a strong and uneven basal texture was formed in the Mg-3Al-0.5Zn sheet. Meanwhile, the intensity of the basal texture was significantly weakened due to the numerous fine precipitates of Mg17Al12 particles, with the Al content increasing, which hinder the grain growth during extrusion, while fine recrystallized grains have a more random orientation. The enhanced tensile properties in Mg-8Al-0.5Zn and Mg-9Al-0.5Zn alloy sheets are ascribed to the cooperation effect of a refined microstructure, precipitates and weakened basal texture. Among the three Mg alloy sheets, the Mg-8Al-0.5Zn alloy sheet has a yield strength of about 270 MPa, an ultimate tensile strength of about 330 MPa and ultimate elongation of about 16% in the extrusion direction, which possesses the most excellent comprehensive mechanical properties.

Metabolomics in Primary Open Angle Glaucoma: A Systematic Review and Meta-Analysis.

Glaucoma is a leading cause of blindness worldwide. It is suggested that primary open angle glaucoma (POAG), the most common form of glaucoma, may be associated with significant metabolic alternations, but the systemic literature review and meta-analysis in the area have been missing. Altered metabolomic profiles in the aqueous humor and plasma may serve as possible biomarkers for early detection or treatment targets. In this article, we performed a systematic meta-analysis of the current literature surrounding the metabolomics of patients with POAG and metabolites associated with the disease. Results suggest several metabolites found to be specifically altered in patients with POAG, suggesting broad generalizability and pathways for future research.

Baicalein-A Potent Pro-Homeostatic Regulator of Microglia in Retinal Ischemic Injury.

Retinal ischemia is a common cause of many retinal diseases, leading to irreversible vision impairment and blindness. Excessive neuroinflammation, including microglial activation and T-cell responses, has been identified as a critical factor associated with neurodegeneration in retinal ischemia. Baicalein is a natural flavonoid reported to have broad anti-inflammatory and neuroprotective bioactivities. Herein, the effects of baicalein on microglia activation in vitro and in vivo were investigated. We found that baicalein exhibited robust anti-inflammatory effect on cultured human and mouse microglia, as demonstrated by decreased induction of pro-inflammatory cytokines and the phosphorylation of phosphoinositide 3-kinase (PI3K) and nuclear factor kappa B (NFκB). Proteomic analysis further unraveled baicalein's effect on modulating IL-17 signaling pathways and its upstream regulator IL-1ß. Intravitreal administration of baicalein in the mouse model of retinal ischemia/reperfusion (I/R) injury attenuated microglial activation and retinal T-cell infiltration, particularly the T helper 17 cells. Additionally, baicalein was shown to exert neuroprotective effects by significantly reducing the retinal ganglion cell (RGC) loss after I/R injury, leading to an improved retinal function and spatial vision. These results suggest that baicalein, a natural flavonoid, acts as a negative regulator of activated microglia and immune responses both in vitro and in vivo, effectively alleviating neurodegeneration in retinal I/R injury. This finding indicates that baicalein could be a potential therapeutic agent against currently incurable degenerative retinal diseases.

High-dose dual therapy versus culture-based susceptibility-guided therapy as a rescue regimen for Helicobacter pylori infection: a randomized controlled trial.

Background: Although the Maastricht VI/Florence consensus report recommended high-dose proton pump inhibitor-amoxicillin dual therapy as possible rescue therapy for Helicobacter pylori infection, clinical evidence of its efficacy was lacking. Objectives: To compare the efficacy, safety, patient compliance, and cost between high-dose dual therapy (HDDT) and culture-based susceptibility-guided therapy (CB-SGT) as a rescue regimen for H. pylori infection. Design: A single-center, open-label, randomized controlled clinical trial. Methods: In all, 146 patients with a history of eradication failure were enrolled and randomly assigned to receive HDDT or CB-SGT. HDDT consisted of esomeprazole 20 mg and amoxicillin 750 mg, both given four times per day (qid). CB-SGT consisted of esomeprazole 20 mg twice daily (bid), amoxicillin 1000 mg bid plus clarithromycin 500 mg bid, metronidazole 400 mg bid, or levofloxacin 500 mg daily (qd) for sensitive patients, in that order. For patients with triple resistance, a bismuth-containing regimen with a high dose of metronidazole was chosen, including esomeprazole 20 mg bid, bismuth 220 mg bid, amoxicillin 1000 mg bid, and metronidazole 400 mg qid. All regimens were given for 14 days. Results: The eradication H. pylori rates achieved with HDDT in the intention-to-treat (ITT), per-protocol, and modified ITT analyses were all 84.9% [62/73, 95% confidence interval (CI): 76.5-93.9%], compared with 83.6% (61/73, 95% CI: 74.9-92.3%), 84.7% (61/72, 95% CI: 76.2-93.2%), and 84.7% (61/72, 95% CI: 76.2-93.2%) with CB-SGT, respectively. For patients with CYP2C19 polymorphisms of intermediate/poor metabolizers, the eradication rates of HDDT and CB-SGT were 90.70% (39/43, 95% CI: 77.86-97.41%) and 84.21% (32/38, 95% CI: 68.75-93.98%), respectively. The difference between groups was 6.49% (95% CI: -8.00% to 20.97%), and the non-inferiority p value was 0.0128. For patients with a treatment interval of more than 3 months, the eradication rates of the two regimens reached 88.71% (95% CI: 78.11-95.34%) and 71.97% (95% CI: 70.02-90.64%). The difference between groups was 6.74% (95% CI: -5.71% to 19.20%), with a non-inferiority p value of 0.0042. Patient adherence was high in both groups. The HDDT had a lower cost and rate of side effects (p < 0.001) compared with CB-SGT. Conclusions: HDDT can reach an eradication rate of 85% in treatment-experienced patients of H. pylori infection and 91% in patients with CYP2C19 polymorphisms of intermediate/poor metabolizers, with good compliance, lower side effects and costs, and less use of antibiotics. In conclusion, HDDT offers an effective rescue regimen for H. pylori infection. Registration: This clinical trial was registered at the Chinese Clinical Trail Registry (trail registration number: ChiCTR1900025044).

The Prevalence of Autoimmune Diseases in Patients with Primary Open-Angle Glaucoma Undergoing Ophthalmic Surgeries.

PURPOSE: To assess the prevalence of autoimmune disease (AiD) in patients with primary open-angle glaucoma (POAG) undergoing ophthalmic surgery. DESIGN: Retrospective, cross-sectional study. PARTICIPANTS: Patients with POAG undergoing any ophthalmic surgery and control subjects undergoing cataract surgery at the Massachusetts Eye and Ear from March 2019 to April 2020. METHODS: All available medical records with patient demographics, ocular, and medical conditions were reviewed. Differences in AiD prevalence were assessed and adjusted for covariates using multiple logistic regression. Additionally, a subgroup analysis comparing the POAG patients with and without AiD was performed. MAIN OUTCOME MEASURES: To assess the prevalence of AiD based on the American Autoimmune Related Diseases Association list. RESULTS: A total of 172 patients with POAG and 179 controls were included. The overall prevalence of AiD was 17.4% in the POAG group and 10.1% in the controls (P = 0.044); 6.4% of POAG patients and 3.4% of controls had more than 1 AiD (P = 0.18). The most prevalent AiDs in POAG group were rheumatoid arthritis (4.6%) and psoriasis (4.1%), which were also the most common in controls (2.8% each). In a fully adjusted multiple logistic regression analysis accounting for steroid use, having an AiD was associated with 2.62-fold increased odds of POAG relative to controls (95% confidence interval, 1.27-5.36, P = 0.009); other risk factors for POAG derived from the analysis included age (odds ratio [OR], 1.04, P = 0.006), diabetes mellitus (OR, 2.31, P = 0.008), and non-White ethnicity (OR, 4.75, P < 0.001). In a case-only analysis involving the eye with worse glaucoma, there was no statistical difference in visual field mean deviation or retinal nerve fiber layer (RNFL) thickness in POAG patients with AiD (n = 30) and without AiD (n = 142, P > 0.13, for both). CONCLUSIONS: A higher prevalence of AiD was found in POAG patients compared with control patients undergoing ophthalmic surgery. The presence of AiD was associated with increased risk for POAG after adjusting for covariates. Additional factors may have prevented a difference in RNFL thickness in POAG patients with and without AiD. Autoimmunity should be explored further in the pathogenesis of POAG.