Preparation of graphene oxide/natural rubber composites by latex co-coagulation: Relationship between microstructure and reinforcement

Graphene oxide(GO)has recently attracted substantial interest as a possible reinforcing agent for next generation rubber composite materials.In this research,GO was incorporated in natural rubber(NR)composites through latex co-coagulation technique.The microstructures of GO/NR composites were characterized through a combination of transmission electron microscope,scanning electron microscope,X-ray diffraction,Fourier transform infrared spectroscopy,and Differential scanning calorimeter.The results showed that highly exfoliated GO sheets were finely dispersed into NR rubber matrix with strong interface interaction between GO and NR.The mechanical properties of the GO/NR composites were further evaluated.The results showed that the tensile strength,tear strength and modulus can be significantly improved at a content of less than 2 phr.Especially,GO exhibited specific reinforce mechanism in NR due to the stress-induced crystallization effects of NR.The stress transfer from the NR to the GO sheets and the hindrance of GO sheets to the stress-induced crystallization of NR were further displayed in stress-strain behavior of GO/NR composites.These enhanced properties were attributed to the high surface area of GO sheets and highly exfoliated microstructures of GO sheets in NR.

Allogeneic sclera graft combined autologous conjunctival flap for repairing the emergent corneal perforation

To report a palliative and alternative surgical procedure, allogeneic sclera graft combined with autologous conjunctival flap (ASGACF), employing to repair the large emergent corneal perforation. The detail protocol of the surgical procedure was characterized and four representative cases were reviewed. An allogeneic sclera graft and recipient bed were prepared as the traditional penetrating keratoplasty (PK). And then sutured the sclera graft to the bed with 10-0 nylon suture and covered with a pedicled autologous conjunctival flap in half size. In the follow-up, the ASGACF repaired all of the corneal perforations and restored the integral walls of eyeballs, in spite of one who underwent a second surgery. This surgical procedure provided a palliative method to repair the large emergent corneal perforation while there is the lack of a corneal graft.

Inhibition of EGFR attenuates EGF-induced activation of retinal pigment epithelium cell via EGFR/AKT signaling pathway

AIM:To explore the effect of epidermal growth factor receptor(EGFR)inhibition by erlotinib and EGFR siRNA on epidermal growth factor(EGF)-induced activation of retinal pigment epithelium(RPE)cells.METHODS:Human RPE cell line(ARPE-19 cells)was activated by 100 ng/mL EGF.Erlotinib and EGFR siRNA were used to intervene EGF treatment.Cellular viability,proliferation,and migration were detected by methyl thiazolyl tetrazolium(MTT)assay,bromodeoxyuridine(BrdU)staining assay and wound healing assay,respectively.EGFR/protein kinase B(AKT)pathway proteins and N-cadherin,α-smooth muscle actin(α-SMA),and vimentin were tested by Western blot assay.EGFR was also determined by immunofluorescence staining.RESULTS:EGF treatment for 24h induced a significant increase of ARPE-19 cells’viability,proliferation and migration,phosphorylation of EGFR/AKT proteins,and decreased total EGFR expression.Erlotinib suppressed ARPE-19 cells’viability,proliferation and migration through down regulating total EGFR and AKT protein expressions.Erlotinib also inhibited EGF-induced an increase of proliferative and migrative ability in ARPE-19 cells and clearly suppressed EGF-induced EGFR/AKT proteins phosphorylation and decreased expression of N-cadherin,α-SMA,and vimentin proteins.Similarly,EGFR inhibition by EGFR siRNA significantly affected EGF-induced an increase of cell proliferation,viability,and migration,phosphorylation of EGFR/AKT proteins,and up-regulation of N-cadherin,α-SMA,and vimentin proteins.CONCLUSION:Erlotinib and EGFR-knockdown suppress EGF-induced cell viability,proliferation,and migration via EGFR/AKT pathway in RPE cells.EGFR inhibition may be a possible therapeutic approach for proliferative vitreoretinopathy(PVR).

Hepatocyte growth factor promotes retinal pigment epithelium cell activity through MET/AKT signaling pathway

AIM:To explore the effects of hepatocyte growth factor(HGF)on retinal pigment epithelium(RPE)cell behaviors.METHODS:The human adult retinal pigment epithelial cell line-19(ARPE-19)were treated by HGF or mesenchymalepithelial transition factor(MET)inhibitor SU11274 in vitro.Cell viability was detected by a Cell Counting Kit-8 assay.Cell proliferation and motility was detected by a bromodeoxyuridine incorporation assay and a wound healing assay,respectively.The expression levels of MET,phosphorylated MET,protein kinase B(AKT),and phosphorylated AKT proteins were determined by Western blot assay.The MET and phosphorylated MET proteins were also determined by immunofluorescence assay.RESULTS:HGF increased ARPE-19 cells’viability,proliferation and migration,and induced an increase of phosphorylated MET and phosphorylated AKT proteins.SU11274 significantly reduced cell viability,proliferation,and migration and decreased the expression of MET and AKT proteins.SU11274 suppressed HGF-induced increase of viability,proliferation,and migration in ARPE-19 cells.Additionally,SU11274 also blocked HGF-induced phosphorylation of MET and AKT proteins.CONCLUSION:HGF enhances cellular viability,proliferation,and migration in RPE cells through the MET/AKT signaling pathway,whereas this enhancement is suppressed by the MET inhibitor SU11274.HGF-induced MET/AKT signaling might be a vital contributor of RPE cells survival.

Expression of visual system homeobox 1 in human keratoconus

AIM: To investigate the expression of visual system homeobox 1(VSX1) and myofibroblast marker alpha smooth muscle actin(α-SMA) in keratoconus(KC). METHODS: Thirty corneal tissue were collected from KC patients after corneal transplantation and 15 normal donor corneas were obtained. All corneal tissues divided into 4 parts for different detections. Scanning electron microscopy was used to observe the ultrastructure of the specimens. VSX1 and α-SMA localization in cornea tissues was detected using immunofluorescence histochemistry. Reverse transcription-quantitative polymerase chain reaction(RT-qPCR) and Western blot were performed to analyze the expression level of VSX1 and α-SMA. RESULTS: Compared to normal cornea tissue, the collagen fibers in KC stroma were distortional and attenuated and keratocytes were abnormally changed. VSX1 and α-SMA located in the corneal stroma. The mRNA and protein expression level of VSX1 in KC were about 3 times as high as that of normal tissue(P<0.001). α-SMA was hardly expressed in the normal corneas, however, its expression in the KC was about 1.5 times higher than that of the normal corneas(P<0.0001). CONCLUSION: Compared with normal corneal the expression of VSX1 and α-SMA in KC both increased. VSX1 is related to the activation of keratocytes and involved in the pathogenesis of keratoconus.

Navigated laser in diabetic macular edema: the impact of reduced injection burden on patients and physicians-who wins and who loses?

We inquired the impact of reduced therapy discontinuation in diabetic macular edema(DME) on physician's revenue considering anti-vascular endothelial growth factor(VEGF) monotherapy and its combination with Navilas treatment. Data were collected on injection frequency, treatment discontinuation and reimbursement fees for DME treatment with anti-VEGF compared to anti-VEGF in combination with navigated laser. Based on these data an economic model was built to compare physicians revenue over a 5y period using either therapy for 4 European countries and the USA. Due to patients' higher therapy adherence, physicians using navigated laser therapy with anti-VEGF generate similar or higher revenues compared to VEGF monotherapy in all analyzed countries. The use of Navilas decreases the patient's injection burden at the same clinical outcome, while the physician's revenue remained stable or increased. Therewith, therapy discontinuation in DME can be reduced using the combination therapy with Navilas.

Prevalence and risk factors of dry eye disease in young and middle-aged office employee:a Xi’an Study

AIM:To estimate the prevalence of and risk factors for dry eye disease(DED)in young and middle-aged office employee in Xi’an.METHODS:This cross-sectional study of the prevalence of and risk factors for DED investigated 486 young and middle-aged Chinese office employee in Xi’an.DED symptoms and potential risk factors were assessed using the ocular surface disease index combined with a risk factors questionnaire,and tear function was evaluated using the tear film break-up time and Schirmer’s test.Possible risk factors for DED were estimated by binary Logistic regression analysis.RESULTS:DED was diagnosed in 100 females and 96 males,giving a prevalence of 40.3%[95%confidence interval(CI)=36.0%-44.7%].The multivariate binary Logistic regression model indicated that the possible risk factors for DED were being female(OR=1.592,95%CI=1.034-2.451,P=0.035),being aged≥40 y(OR=1.593,95%CI=1.034-2.454,P=0.035),using a VDT daily for>6 h(OR=1.990,95%CI=1.334-2.971,P=0.001),the presence of central air conditioning(OR=1.548,95%CI=1.053-2.276,P=0.026),and self-reported dryness of the mouth and nose(OR=1.589,95%CI=1.071-2.357,P=0.021).CONCLUSION:There is a high prevalence of clinically diagnosed DED in young and middle-aged video displayterminal(VDT)users.Interventions against the modifiable risk factors should be taken to prevent the occurrence and development of DED in this population.

YM155 inhibits retinal pigment epithelium cell survival through EGFR/MAPK signaling pathway

AIM:To investigate YM155’s effect on retinal pigment epithelium(RPE)cells’viability and the potential regulatory mechanisms.METHODS:Human immortalized RPE cell lines(ARPE-19 cell line)were processed with YM155 and epidermal growth factor(EGF).ARPE-19 cell viability was detected by methyl thiazolyl tetrazolium assay,and apoptosis was tested by flow cytometry assay.ARPE-19 cell proliferation was assessed with bromodeoxyuridine tagged incorporation assay,and migration ability was evaluated via a wound-healing assay.Epidermal growth factor receptor(EGFR)/MAPK pathway proteins were tested via immunoblotting.EGFR localization was examined by immunofluorescence assay.RESULTS:YM155 suppressed ARPE-19 cells’viability in a time and concentration-dependent manner.A high dose of YM155 caused a small amount of ARPE-19 cell death.YM155 significantly diminished the ARPE-19 cells’proliferative and migrative capacity.YM155 downregulated total EGFR and phosphorylated external signalregulated protein kinase(ERK),and it up-regulated the phosphorylation of P38 MAPK and c-Jun N-terminal kinase(JNK).YM155 induced endocytosis of EGFR in ARPE-19 cell.YM155 also attenuated EGF-induced ARPE-19 cells’proliferative and migrative capacity.Moreover,YM155 significantly decreased the expression of phosphorylated EGFR and ERK after treated by EGF.CONCLUSION:YM155 inhibits RPE cell survival,the cell proliferative and migrative capacity,and it effectuates a small amount of cell death through the EGFR/MAPK signaling pathway.YM155 might,therefore,be an agent to prevent and treat abnormal RPE cell survival in proliferative vitreoretinopathy.

Decreased uncoupling protein 2 expression in aging retinal pigment epithelial cells

AIM: To analyze the expression of uncoupling protein 2(UCP2) in retinal pigment epithelium(RPE) cells at the different human age, further explore the possible new target of RPE cells protection.METHODS: Adult retinal pigment epithelial-19(ARPE-19) cells and the primary RPE cells at the different age(9-20 y,50-55 y, 60-70 y, >70 y) were cultured and harvested. The expression of UCP2 in these cells was detected by reverse transcription-polymerase chain reaction(RT-PCR), Western blot and confocal microscopy.RESULTS: Cells from the donors more than 60 y are larger and more fibroblastic in appearance compared to ARPE-19 cells and those primary cultures obtained from the younger individuals by using phase-contrast micrographs. Results of RT-PCR, Western blot and confocal microscopy all showed that UCP2 was highly expressed in ARPE-19 cells and in the younger primary cultured human RPE cells at the age of 9-20 y and 50-55 y, whereas lower expression of UCP2 was measured in the older primary cultured human RPE cells at the age more than 60 y.CONCLUSION: Expression of UCP2 gene is decreased in aged RPE cells, promoting the lower ability of anti-oxidation in these cells. It is indicated that UCP2 gene might be a new target for protecting the cells from oxidative stress damage.

Corneal stromal mesenchymal stem cells: reconstructing a bioactive cornea and repairing the corneal limbus and stromal microenvironment

Corneal stroma-derived mesenchymal stem cells(CS-MSCs) are mainly distributed in the anterior part of the corneal stroma near the corneal limbal stem cells(LSCs). CS-MSCs are stem cells with self-renewal and multidirectional differentiation potential. A large amount of data confirmed that CS-MSCs can be induced to differentiate into functional keratocytes in vitro, which is the motive force for maintaining corneal transparency and producing a normal corneal stroma. CS-MSCs are also an important component of the limbal microenvironment. Furthermore, they are of great significance in the reconstruction of ocular surface tissue and tissue engineering for active biocornea construction. In this paper, the localization and biological characteristics of CS-MSCs, the use of CS-MSCs to reconstruct a tissue-engineered active biocornea, and the repair of the limbal and matrix microenvironment by CS-MSCs are reviewed, and their application prospects are discussed.

Short-term effect of 0.01% atropine sulphate eye gel on myopia progression in children

AIM: To investigate the effect of 0.01% atropine sulphate eye gel on myopia progression and axial elongation in a 6-month treatment in children.METHODS: Totally 185 children aged 6-12 y with binocular myopia of 3.0 D or less in both eyes were enrolled in this prospective cohort study. The atropine group(n=125) received one drop of 0.01% atropine sulphate eye gel in each eye before bedtime daily. The control group included 60 matched children without drug intervention during the same period. The spherical equivalent and axial length was recorded at baseline and the sixth month of treatment. The efficacy was evaluated by the change of the spherical equivalent and axial length. Adverse events were also recorded.RESULTS: The average spherical equivalent and axial length at baseline were not statistically significant between the atropine group(-1.64±0.80 D, 24.13±0.76 mm) and the control group(-1.59±0.94 D, 24.06±0.77 mm, P>0.05). After 6 mo, there was significantly difference in the spherical equivalent progression between the atropine and the control group(-0.27±0.33 vs-0.60±0.35 D, P<0.001),with a relative reduction of 55.0% in myopia progression. The increase in axial elongation in the atropine group was significantly less than control group(0.19±0.14 vs 0.26±0.14 mm, P<0.001), with a relative reduction of 26.9% in axial length. The 84.4% and 38.4% of the eyes progressed by less than 0.50 D and remained stable in the atropine group, compared with 51.7% and 4.2% in the control group. No adverse events were observed.CONCLUSION: Atropine sulphate eye gel 0.01% can slow down myopia progression and axial elongation in children with a 6-month treatment.

Down regulation of UCP2 expression in retinal pigment epithelium cells under oxidative stress: an in vitro study

AIM: To evaluate the expression of uncoupling protein 2(UCP2) in a retinal pigment epithelium cell line(ARPE-19), under oxidative stress(OS).METHODS: ARPE-19 cells were divided into groups treated with various concentrations of hydrogen peroxide(H2 O2;0, 150, 300, 500, 700, and 900 μmol/L) for 24 h, to induce oxidative damage and cell viability was assessed by MTT assay. UCP2 mRNA expression in cells treated with H2 O2 was investigated by reverse transcription-polymerase chain reaction(RT-PCR). UCP2 protein expression was assessed by Western blotting and ROS levels analyzed by flow cytometry(FCM). Further, UCP2-siRNA treated cultures were exposed to H2 O2(0, 75, 150, and 300 μmol/L) for 2 h and cell viability determined by MTT assay.RESULTS: Cells treated with higher concentrations of H2 O2 appeared shrunken;their adhesion to adjacent cells was disrupted, and the number of dead cells increased. The results of cell viability assays demonstrated that the numbers of cells were decreased in a dose-dependent manner following treatment with H2 O2. Compared with untreated controls, cell viability was significantly reduced after treatment with >300 μmol/L H2 O2(P<0.05). Cell metabolic activity was decreased with increased concentrations of H2 O2 as detected by MTT assay. Levels of OS were further decreased in cells treated with UCP2-siRNA compared with those treated with H2 O2 alone(P<0.05). The results of RT-PCR and Western blotting demonstrated that UCP2 expression was reduced in H2 O2-treated groups compared with controls(P<0.05). FCM analysis showed that cell reactive oxygen species(ROS) levels were increased in H2 O2-treated groups and further upregulated by UCP2-si RNA treatment(P<0.05).CONCLUSION: Expression levels of UCP2 are decreased in ARPE-19 cells treated with H2 O2. ROS levels are further increased in cells treated with UCP2-siRNA relative to those treated with H2 O2 alone. UCP2 may have a protective role in ARPE-19 cells during oxidative injury.

Comparison of healing patterns of different side-cut angulations after FS-LASIK

AIM: To investigate and evaluate healing patterns around flaps made with different side-cut angulations after femtosecond laser in situ keratomileusis(FS-LASIK).METHODS: Thirty-four patients(68 eyes) received a 90° side-cut(n=34) or a 120° side-cut flaps(n=34) made with a femtosecond laser. One day, 1 wk, 1 and 3 mo postoperatively, side-cut scar was evaluated under slit-lamp photography according to a new grading system(Grade 0=transparent scar, 1=faint healing opacity, and 2=evident healing opacity). In vivo corneal confocal microscopy and anterior segment optical coherence tomography(AS-OCT) were used to observe wound-healing patterns around flap margin in the two groups. Sirius Scheimpflug Analyzer was also used to analyze higher order aberrations 3 mo after surgery.RESULTS: There were no significant differences in flap wound-healing patterns at each follow up between the two groups(P>0.05). Three months after surgery, the flap edge scar classified as Grade 0 had excellent apposition and rapid nerve regeneration. At 3 mm and 5 mm pupil diameters, there were significant differences in trefoil aberrations between the two groups(P<0.05), but no statistically significant differences were found in total higher order aberrations(HOAs), spherical aberrations or coma in any of the pupil size conditions(P>0.05).CONCLUSION: Flap edge scars classified as Grade 0 have excellent apposition and rapid nerve regeneration, and 120° side-cut angle flaps induce less trefoil aberrations after FS-LASIK.

A multi-omics study on cutaneous and uveal melanoma

AIM:To present the multi-omics landscape of cutaneous melanoma(CM)and uveal melanoma(UM)from The Cancer Genome Atlas(TCGA).METHODS:The differentially expressed genes(DEGs)between CM and UM were found and integrated into a gene ontology enrichment analysis.Besides,the differentially expressed miRNAs were also identified.We also compared the methylation level of CM with UM and identified the differentially methylated regions to integrate with the DEGs to display the relationship between the gene expression and DNA methylation.The differentially expressed transcription factors(TFs)were identified.RESULTS:Though CM had more mutational burden than UM,they shared several similarities such as the same rankings in diverse variant types.Except GNAQ and GNA11,the other top 18 mutated genes of the combined group were mostly detected in CM instead of UM.On the transcriptomic level,4610 DEGs were found and integrated into a gene ontology enrichment analysis.We also identified 485 differentially expressed miRNAs.The methylation analysis showed that UM had a significantly higher methylation level than CM.The integration of differentially methylated regions and DEGs demonstrated that most DEGs were downregulated in UM and the hypo-and hypermethylation presented no obvious difference within these DEGs.Finally,116 hypermethylated TFs and 114 hypomethylated TFs were identified as differentially expressed TFs in CM when compared with UM.CONCLUSION:This multi-omics study on comparing CM with UM confirms that they differ in all analyzed levels.Of notice,the results also offer new insights with implications for elucidating certain unclear problems such as the distinct role of epithelial mesenchymal transition in two melanomas,the different metastatic routes of CM and UM and the liver tropism of metastatic UM.

老年性黄斑变性脉络膜及视网膜色素上皮细胞的自体易位研究

Purpose:To evaluate the autologous translocation of peripheral choroid and retinal pigment epithelium(RPE)in 45 eyes of 43 patients with age-related macular degeneration(AMD).Design:Prospective nonrandomized study.Methods:All patients had visual loss due to AMD(n=5 classic membranes,n=14 occult,n=2 mixed,n=16 pigment epithelial detachment(PED),n=5 subretinal hemorrhage,n=3 geographic atrophy).After extraction of the neovascular complex,an autologous peripheral full-thickness explant of RPE,Bruch membrane,and choroid was translocated from the midperiphery to themacula.Results:Preoperative distant visual acuity ranged from 20/800 to 20/40.Reading vision ranged from 1.4 logarithm of reading acuity determination(logRAD)to 0.5 logRAD(0.04 to 0.32 Snellen equivalent).Revision surgery was required in 22 eyes as a result of proliferative vitreoretinopathy(PVR),retinal detachment,macular pucker,or vitreous hemorrhage.In eight patients,the patch was renewed.At six months,distant visual acuity ranged from light perception to 20/50(increase of 15 letters in four eyes).Reading vision ranged from 1.4 to 0.4 logRAD.Visual outcome was unrelated to the type of AMD.Vascularization of the transplant was visible on indocyanine green(ICG)angiography in 40 of 42 eyes.In most patients,autofluorescence of the pigment epithelium was coincident with revascularization of the graft.Fixation on the patch was positively related to visual acuity.Conclusions:Autologous translocation of a full thickness transplant of choroid and RPE usually results in a vascularized and functioning graft.Vascularization was even achieved in patients with geographic atrophy.Fixation stability and microperimetry before the patch translocation may be helpful in selecting patients who will profit from surgery.