Conjunctival sac flora and drug susceptibility analysis in normal children in East China.

PURPOSE: To investigate the distribution characteristics of conjunctival sac flora and assess the susceptibility of commonly used topical antimicrobial agents in normal children under the age of 18 in East China. METHODS: In 2019, a study was conducted at Qingdao Eye Hospital of Shandong First Medical University to analyze the microorganism cultures of conjunctival sac in 1258 normal children (2516 eyes; average age, 6.21 ± 3.78 years) in East China. Exclusion criteria included children with ocular surface diseases and those who had used any topical antimicrobial agents recently. The microorganism species in the conjunctival sac were analyzed using the M-38A protocol (microdilution method; investigators read the minimum inhibitory concentration [MIC] values) by the Clinical and Laboratory Standards Institute to determine drug susceptibility. RESULTS: The incidence of conjunctival sac microorganism in children was 32.87% (827/2516), a total of 541 cases (male 293, female 248). Children with conjunctival sac flora in a single eye were 255 and in both eyes were 286 (no statistical difference, P > 0.05). The concordance rate of children with binocular conjunctival sac flora was 32.16% (174/541; male 84, female 90). A total of 42 species of bacteria were detected. Children with Gram-positive cocci accounted for the highest proportion, 91.54% (757/827). The top three bacteria with the highest detection rates were Staphylococcus epidermidis (S. epidermidis; 52.12%), Streptococcus (12.09%), and Staphylococcus aureus (S. aureus; 10.76%). Streptococcus mitis (5.20%) accounted for the highest proportion of Streptococcus.S. epidermidis had the highest proportion in all age groups and was positively correlated with age (r = 0.89, P = 0.03). Before six years of age, the streptococcal proportion(mainly S. mitis) was greater than that of Staphylococcus aureus. The drug susceptibility analysis showed that S. epidermidis was most sensitive to gatifloxacin (98.61%), while it had the highest resistance rate to erythrocin (87.94%). S. aureus had the highest susceptibility to moxifloxacin (100%). Streptococcus was most sensitive to moxifloxacin (96.97%) and had the highest resistance rate to tobramycin (92.93%). CONCLUSIONS: Conjunctival sac flora in children was dominated by Gram-positive cocci, mainly S. epidermidis, S. aureus, and Streptococcus. S. epidermidis increased with age; the proportion of Streptococcus was higher than S. aureus among children aged 0-6 years. The typical conjunctiva sac flora was generally sensitive to quinolones, such as moxifloxacin and gatifloxacin; Streptococcus displayed high resistance to tobramycin antibiotics; and the female children had higher resistance to tobramycin than the male children.

Unilateral chronic angle-closure glaucoma in a pediatric patient with neurofibromatosis: a case report.

Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic disease that causes multi-system damage. It is rarely associated with angle-closure glaucoma, especially in pediatric patients. We herein report a case of unilateral chronic angle-closure glaucoma in a patient with NF1. A 5-year-old girl with a large subcutaneous soft mass and multiple scattered coffee-milk spots presented with low vision, increased intraocular pressure, and angle closure in her right eye. Lisch nodules were seen in both eyes. In her right eye, ectropion uveae was observed at the top and bottom margins of the pupil. Magnetic resonance imaging of the skull and orbit revealed no abnormalities. Finally, trabeculectomy was performed on the right eye, after which the right eye showed a stable intraocular pressure. NF1 combined with angle-closure glaucoma is rare and easily missed in the clinical setting. Early diagnosis and treatment may achieve good results.

Inhibition of Heat Shock Protein B8 Alleviates Retinal Dysfunction and Ganglion Cells Loss Via Autophagy Suppression in Mouse Axonal Damage.

Purpose: Heat shock protein B8 (HspB8) can be upregulated rapidly in many pathologic processes, but its role in traumatic optic neuropathy remains unclear. In this study, we investigated the involvement of autophagy in the effects of HspB8 by using the optic nerve crush (ONC) model. Methods: Male C57BL/6J mice were intravitreally injected with recombinant adeno-associated virus type 2 (AAV2-shHspB8 or AAV2-GFP) and subsequently received ONC by a self-closing tweezers. Western blot and immunohistochemistry staining were used to evaluate the expression of HspB8. We conducted retinal flat-mount immunofluorescence to measure the quantities of retinal ganglion cells (RGCs), and full-field flash electroretinogram (ff-ERG) and optomotor response (OMR) were used to evaluate retinal function. The autophagy level was reflected by western blot, immunohistochemistry staining, and transmission electron microscope (TEM) images. We also applied 3-methyladenine (3MA) and rapamycin (Rapa) to regulate autophagy level in optic nerve injury. Results: ONC stimulated the expression of HspB8. Declines of RGCs and ff-ERG b-wave amplitudes resulting from ONC can be alleviated by HspB8 downregulation. Increased autophagy activity after ONC was observed; however, this change can be reversed by intravitreal injection of AAV2-shHspB8. Furthermore, application of autophagy inhibitor 3MA had the same neuroprotective effects as AAV2-shHspB8, as illustrated by ff-ERG and quantities of RGCs. Also, protection of AAV2-shHspB8 was compromised by the autophagy activator Rapa. Conclusions: Inhibition of HspB8 in mice optic nerve injury had neuroprotective effects, which may be derived from its downregulation of autophagy.

Krüppel-like factor 7 protects retinal ganglion cells and promotes functional preservation via activating the Akt pathway after retinal ischemia-reperfusion injury.

OBJECTIVE: The purpose of this study is to investigate the effects of Krüppel-like factor 7 (KLF7) on retinal ganglion cells (RGCs) and retinal function after retinal ischemia-reperfusion (RIR) injury in mice. METHODS: Male C57BL/6J mice were intravitreally injected with recombinant adeno-associated vectors (rAAV-KLF7-EGFP or rAAV-EGFP), and subsequently used to induce RIR injury. Retinal cryosections were used to access the efficacy of virus transfection, 1, 2, 3, and 4 weeks after rAAV-KLF7-EGFP transfer. RGCs survival rate was observed and quantified by immunofluorescent staining, 7 days after RIR injury. Meanwhile, electroretinogram (ERG) and optomotor response were used to evaluate the electrophysiological functions and visual acuity. Apoptosis was evaluated by TUNEL staining 1 day after RIR injury. Expression of KLF7, Akt, phospho-Akt, Bcl-2, and Bax were further detected by western blot to excavate the underlying mechanism. RESULTS: The transfection efficiency of rAAV-KLF7-EGFP was increased in a time-dependent manner, and the number of EGFP-positive cells was increased significantly 3 weeks after rAAV-KLF7-EGFP transfer. RGCs survival rates, amplitudes of ERG a-, b-wave, Ops, PhNR, and visual acuity of mice were decreased after RIR injury. With the increase of light intensity, the amplitudes of scotopic ERG a- and b-wave were gradually increased while the incubation period was gradually shortened. RGCs survival rates, amplitudes of ERG a-, b-wave, Ops, PhNR, and visual acuity of mice were increased after rAAV-KLF7-EGFP transfer. The protein level of KLF7 was up-regulated after rAAV-KLF7-EGFP transfer. Up-regulation of KLF7 significantly inhibited cells apoptosis, increased phospho-Akt and Bcl-2 expression, and decreased Bax expression. There were no significant changes in Akt expression. CONCLUSION: Overexpression of KLF7 can not only prevent the loss of RGCs, but also preserve the electrophysiological function. In addition, overexpression of KLF7 can ameliorate the retinal dysfunction after RIR injury, and ultimately improve the visual acuity of mice. The activation of Akt pathway and the suppression of the mitochondrial apoptotic pathway contribute to the neuroprotection of KLF7.

Bioinformatics analysis of multi-omics data identifying molecular biomarker candidates and epigenetically regulatory targets associated with retinoblastoma.

Retinoblastoma (RB) is the commonest malignant tumor of the infant retina. Besides genetic changes, epigenetic events are also considered to implicate the occurrence of RB. This study aimed to identify significantly altered protein-coding genes, DNA methylation, microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and their molecular functions and pathways associated with RB, and investigate the epigenetically regulatory mechanism of DNA methylation modification and non-coding RNAs on key genes of RB via bioinformatics method.We obtained multi-omics data on protein-coding genes, DNA methylation, miRNAs, and lncRNAs from the Gene Expression Omnibus database. We identified differentially expressed genes (DEGs) using the Limma package in R, discerned their biological functions and pathways using enrichment analysis, and conducted the modular analysis based on protein-protein interaction network to identify hub genes of RB. Survival analyses based on The Cancer Genome Atlas clinical database were performed to analyze prognostic values of key genes of RB. Subsequently, we identified the differentially methylated genes, differentially expressed miRNAs (DEMs) and lncRNAs (DELs), and intersected them with key genes to analyze possible targets of the underlying epigenetic regulatory mechanisms. Finally, the ceRNA network of lncRNAs-miRNAs-mRNAs was constructed using Cytoscape.A total of 193 DEGs, 74 differentially methylated-DEGs (DM-DEGs), 45 DEMs, 5 DELs were identified. The molecular pathways of DEGs were enriched in cell cycle, p53 signaling pathway, and DNA replication. A total of 10 key genes were identified and found significantly associated with poor survival outcome based on survival analyses, including CDK1, BUB1, CCNB2, TOP2A, CCNB1, RRM2, KIF11, KIF20A, NDC80, and TTK. We further found that hub genes MCM6 and KIF14 were differentially methylated, key gene RRM2 was targeted by DEMs, and key genes TTK, RRM2, and CDK1 were indirectly regulated by DELs. Additionally, the ceRNA network with 222 regulatory associations was constructed to visualize the correlations between lncRNAs-miRNAs-mRNAs.This study presents an integrated bioinformatics analysis of genetic and epigenetic changes that may be associated with the development of RB. Findings may yield many new insights into the molecular biomarker candidates and epigenetically regulatory targets of RB.