Anterior segment optical coherence tomography for superficial keratectomy.

PURPOSE: To report the use of anterior segment optical coherence tomography (AS-OCT) for superficial keratectomy (SK) in anterior corneal opacity. METHODS: The characteristics of 43 eyes (39 patients) with various lesions responsible for anterior corneal opacity were included in this retrospective non-comparative study. AS-OCT was performed on all eyes before surgery. The thickness of corneal opacity and the underlying healthy stroma were measured. SK was performed on each individual. RESULTS: Four types of anterior corneal opacity were evaluated, including corneal degeneration (26/43), Reis-Bücklers corneal dystrophy (8/43), alkali burn (1/43) and corneal tumors (8/43). Based on AS-OCT images, all eyes showed abnormal hyper-reflective signals in the superficial cornea to less than one-third of the normal corneal thickness in the deepest corneal opacity. All 43 eyes underwent an SK procedure. In addition, 1 eye with alkali burns and 7 eyes with corneal tumors were combined with amniotic membrane transplantation. All eyes restored transparency without significant complications. CONCLUSION: AS-OCT is a valuable method for objective preoperative and noninvasive assessments of anterior corneal opacities and is useful for guiding SK.

Comparison of photodynamic therapy with two different parameters combined with subconjunctival injection of bevacizumab for corneal neovascularization.

BACKGROUND: To the best of our knowledge, no studies have been performed to determine the optimal parameters of photodynamic therapy (PDT) combined with subconjunctival injection of bevacizumab for corneal neovascularization. This study aimed to compare the effect of photodynamic therapy with two different sets of parameters combined with subconjunctival injection of bevacizumab for corneal neovascularization. METHODS: Patients with stable corneal neovascularization (CNV) unresponsive to conventional treatment (topical steroid) were included in this study. Patients were divided into two groups, receiving PDT with two different sets of parameters (group 1 receiving fluence of 50 J/cm2 at 15 min after intravenous injection of verteporfin with, group 2 receiving fluence of 150 J/cm2 at 60 min after intravenous injection of verteporfin with). Subconjunctival injection of bevacizumab was performed immediately after PDT. All patients were followed for 6 months. Best-corrected visual acuity and intraocular pressure were evaluated, and slit-lamp biomicroscopy as well as digital photography were performed. Average diameter and cumulative length of corneal neovascular were measured to evaluate the corneal neovascularization. RESULTS: Seventeen patients (20 eyes) were included in this study. At the last visit, the vision was improved in 12 eyes (60 %), steady in 4 eyes (20 %) and worsen in 4 eyes (20 %). The intraocular pressure (IOP) of all patients remained in normal range. A significant decrease in corneal neovascularization was showed in all the eyes after treatment. At 6 months after the combined treatment, the average diameter and cumulative length of vessels significantly decreased to 0.041 ± 0.023 mm (P < 0.05) and 18.78 ± 17.73 mm (P < 0.05), respectively, compared with the pretreatment data (0.062 ± 0.015 mm, 31.48 ± 18.21 mm). The reduction was more remarkable in group 2 compared to group 1.In group 1, the average diameter was 0.062 ± 0.013mm before and 0.056 ± 0.017mm after, the cumulative length of vessels was 38.66 ± 22.55mm before and 31.21 ± 17.30 after. In group 2, the date were 0.061 ± 0.016mm before and 0.029 ± 0.020mm after, 25.60 ± 8.95 mm before and 8.61 ± 8.26 mm. The reported complications included epithelial defect in four eyes, small white filaments in two eyes and corneal epithelial erosion in two eyes. CONCLUSION: The PDT combined with subconjunctival injection of bevacizumab was effective for the chronic corneal neovascularization. A more promising treatment outcome was observed when PDT was performed at 60 min after intravenous injection of verteporfin with fluence of 150 J/cm2. No serious complications or systemic events were observed throughout the follow-up period.

Successful regression of newly formed corneal neovascularization by subconjunctival injection of bevacizumab in patients with chemical burns.

Purpose: To investigate the effect and timing of subconjunctival bevacizumab injection on inhibiting corneal neovascularization (CorNV) in patients after chemical burns. Methods: Patients with CorNV secondary to chemical burns were involved. Two subconjunctival injections of bevacizumab (2.5 mg/0.1 mL per involved quadrant) with an interval of 4 weeks were administered, and followed up a year. The area occupied by neovascular vessels (NA), accumulative neovascular length (NL), mean neovascular diameter (ND), best-corrected visual acuity (BCVA) and intraocular pressure (IOP) were evaluated. Complication was also recorded. Results: Eleven patients with CorNV were involved. Eight patients had a history of surgery (four had amniotic grafts, one had keratoplasty, and three had amniotic grafts and keratoplasty). Decreasing in NA, NL, and ND were statistically significant at each time point compared to the baseline (p < 0.01). CorNV that developed within 1 month was considerably regressed, and vessels with fibrovascular membranes were found to be narrower and shorter than pretreatment. BCVA improved in five patients (from one to five lines), remained unchanged in five patients, and decreased in one patient compared to pretreatment. Conclusion: Subconjunctival bevacizumab injection has a particular potential for the regression of CorNV, especially newly formed within 1 month in patients after chemical burns.

PABPN1 aggregation is driven by Ala expansion and poly(A)-RNA binding, leading to CFIm25 sequestration that impairs alternative polyadenylation.

Poly(A)-binding protein nuclear 1 (PABPN1) is an RNA-binding protein localized in nuclear speckles, while its alanine (Ala)-expanded variants accumulate as intranuclear aggregates in oculopharyngeal muscular dystrophy. The factors that drive PABPN1 aggregation and its cellular consequences remain largely unknown. Here, we investigated the roles of Ala stretch and poly(A) RNA in the phase transition of PABPN1 using biochemical and molecular cell biology methods. We have revealed that the Ala stretch controls its mobility in nuclear speckles, and Ala expansion leads to aggregation from the dynamic speckles. Poly(A) nucleotide is essential to the early-stage condensation that thereby facilitates speckle formation and transition to solid-like aggregates. Moreover, the PABPN1 aggregates can sequester CFIm25, a component of the pre-mRNA 3'-UTR processing complex, in an mRNA-dependent manner and consequently impair the function of CFIm25 in alternative polyadenylation. In conclusion, our study elucidates a molecular mechanism underlying PABPN1 aggregation and sequestration, which will be beneficial for understanding PABPN1 proteinopathy.

Chemerin promotes the pathogenesis of preeclampsia by activating CMKLR1/p-Akt/CEBPɑ axis and inducing M1 macrophage polarization.

A higher ratio of M1/M2 macrophages and an elevated chemerin level are both related to increased risk of preeclampsia. However, the crosstalk between these two events and their collective contribution to preeclampsia are not well understood. In this study, we assessed the impacts of chemerin chemokine-like receptor 1 (CMKLR1)/p-Akt/CEBPα axis in regulating macrophage polarization and mediating the pathogenic effects of chemerin on preeclampsia. We showed that chemerin, in a dose- and time-dependent manner, stimulated M1 macrophage polarization, inhibited macrophage-induced trophoblast invasion and migration, and suppressed macrophage-mediated angiogenesis. All these chemerin-induced phenotypes are essentially mediated by sequentially CMKLR1, Akt activation, and CEBPα. Mechanistically, CEBPα acted as a transcriptional activator for both IRF8 and chemerin. In vivo, chemerin aggravated preeclampsia, while α-NETA, an inhibitor for CMKLR1, significantly suppressed M1 macrophage polarization and alleviated preeclampsia. In summary, chemerin, by activating CMKLR1/Akt/CEBPα axis, forms a positive feedback loop, promotes M1 macrophage polarization, suppresses trophoblast migration/invasion and angiogenesis, and contributes to preeclampsia. Therefore, targeting chemerin signaling may benefit the prevention and/or treatment of preeclampsia.

Early Application of Bevacizumab After Sclerocorneal Grafting for Patients With Severe Late-Stage Ocular Chemical Burns.

PURPOSE: To investigate whether subconjunctival bevacizumab help prevent corneal graft neovascularization and prolong the graft survival of patients with chemical burns. METHODS: We performed a prospective nonrandomized comparative case series study. Twenty-six eyes received subconjunctival bevacizumab (10 mg/0.4 mL) once and topical immunosuppressive agents after sclerocorneal lamellar keratoplasty as the treatment, and 13 eyes received a topical immunosuppressant alone and served as the control group. The main outcomes were a cumulative probability of graft survival, development of corneal neovascularization, and complications. RESULTS: The postoperative follow-up time was 14.3 months (range, 2-62 mo). The cumulative graft survival time was significantly longer in the treatment group than that in the control group (42.9 ± 5.9 vs. 4.8 ± 0.7 mo; log rank < 0.001). In the treatment group, 19 of the 26 grafts (73.1%) survived as transparent with a mean follow-up of 18.7 ± 3.0 months. At the end of the follow-up, 4 grafts remained free of neovascularization, 2 developed edema without neovascularization, and 15 remained transparent with a stable ocular surface and some neovascular vessels in the peripheral transplant interface. The other 5 grafts became opaque and neovascularized. In the control group, all grafts became opaque and neovascularized within the follow-up period (5.5 ± 0.7 mo). During the follow-up, a corneal epithelial defect developed in 9 eyes in the treatment group and 7 in the control group. CONCLUSIONS: Early application of subconjunctival bevacizumab after sclerocorneal lamellar keratoplasty can significantly prevent corneal neovascularization and promote graft survival for severe late-stage ocular chemical burns.

Visual Acuity and Size of Choroidal Neovascularization in Highly Myopic Eyes with a Dome-Shaped Macula.

INTRODUCTION: A dome-shaped macula (DSM) is an inward convexity or anterior deviation of the macular area. DSM is believed as a protective factor in maintaining visual acuity in highly myopic eyes. OBJECTIVE: To investigate the correlation between best-corrected visual acuity (BCVA), choroidal neovascularization (CNV), and a dome-shaped macula (DSM) in highly myopic eyes. METHODS: In this retrospective and observational case series study, BCVA tests and optical coherence tomography (OCT) were performed in a total of 472 highly myopic eyes (refractive error ≥6.5 diopters or axial length ≥26.5 mm). CNV was detected by fundus fluorescein angiography (FFA), and the CNV area was measured by ImageJ software. BCVA, central retinal thickness (CRT), and the CNV area were compared between highly myopic eyes with and without DSM. RESULTS: The data revealed 13 eyes with DSM complicated by CNV, for an estimated prevalence of 25%. The eyes with CNV in the DSM group showed worse BCVA than those in the non-DSM group (1.59 ± 0.69 and 0.63 ± 0.64, respectively, p < 0.05), and the CNV area in the DSM group was larger than that in the non-DSM group (2793.91 ± 2181.24 and 1250.71 ± 1210.36 pixels, respectively, p < 0.05). After excluding the eyes with CNV, the DSM group had better BCVA than the non-DSM group (0.33 ± 0.17 and 0.44 ± 0.48, respectively, p < 0.05); however, no significant difference was observed in the CRT of eyes with CNV between the DSM group and the non-DSM group. CONCLUSION: These results show that DSM might be a protective mechanism for visual acuity, but its protective capability is limited. DSM eyes have better visual acuity within the protective capability. If a more powerful pathogenic factor exceeding the protective capability is present, then the eye will have more severe CNV and worse visual acuity.

Case report of ocular Kaposi's sarcoma.

BACKGROUND: Kaposi's sarcoma (KS) is generally considered a neoplastic disorder of vascular origin and occurs in patients with acquired immunodeficiency syndrome (AIDS) or who have received immunosuppressive treatments after an organ transplant (Soulier et al., Blood 86(4):1276-80, 1995; Viejo-Borbolla and Schulz, AIDS Rev 5(4):222-9, 2003; Schulz, J Antimicrob Chemother 45(Suppl T3):15-27, 2000; Aversa et al. Crit Rev Oncol Hematol 53(3):253-65, 2005; Mbulaiteye and Engels, Int J Cancer 119(11):2685-91, 2006; Tessari et al., Eur J Dermatol 16(5):553-7, 2006). Several Kaposi's sarcoma case reports involving eyelids and conjunctiva have been published (Bavishi et al., Int J STD AIDS 23(3):221-2, 2012; Baumann et al., Ger J Ophthalmol 4(4):239-45, 1995). CASE PRESENTATION: we report a 13 years old asian male patient rare case of ocular KS that was initiated from the sclera and progressed into the cornea and conjunctiva without an human Immunodeificiency Virus (HIV) or HHV-8 infection after a peripheral blood stem cells transplantation. In this case, anti- vascular endothelial growth factor (VEGF) therapy was attempted to stop the advance of ocular lesions and failed. Eventually, the KS was cured by a limbo-corneal lamellar graft, an amniotic membrane and scleral allograft transplantation plus intraoperative mitomycin C(MMC) after the complete excision of the tumors. CONCLUSION: A compete surgical excision combined with the intraoperative application of MMC, as well as grafts to repair the scleral, conjunctival, and corneal surfaces, could prevent a recurrence of KS.

Two mutations G335D and Q343R within the amyloidogenic core region of TDP-43 influence its aggregation and inclusion formation.

TDP-43 is a DNA/RNA binding protein associated with TDP-43 proteinopathies. Many mutations have been identified in the flexible C-terminal region, which is implicated in the disease pathology. We investigated four point mutations in the amyloidogenic core region (residues 311-360) of TDP-43 by biochemical and spectroscopic methods. We found that the G335D mutation enhances the aggregation and inclusion formation of TDP-43 and this mutant in TDP-35 (the C-terminal fragment of 35 kDa) exaggerates the antagonist effect on RNA processing by endogenous TDP-43; whereas Q343R gives an opposite effect. As a comparison, M337V and Q331K have very little impact on the aggregation and inclusion formation of TDP-43 or TDP-35. NMR structural analysis showed that the G335D mutant in the core region forms a loop linker between the two α-helices and promotes α-to-ß transition, but Q343R loses the second helix and consequently the structural transformation. Thus, the propensity of structural transformation in the amyloidogenic core of TDP-43 determines its aggregation and inclusion formation. This study may provide a molecular mechanism of the TDP-43 proteinopathies caused by genetic mutations.

Minocycline inhibits alkali burn-induced corneal neovascularization in mice.

The purpose of this study was to investigate the effects of minocycline on alkali burn-induced corneal neovascularization (CNV). A total of 105 mice treated with alkali burns were randomly divided into three groups to receive intraperitoneal injections of either phosphate buffered saline (PBS) or minocycline twice a day (60 mg/kg or 30 mg/kg) for 14 consecutive days. The area of CNV and corneal epithelial defects was measured on day 4, 7, 10, and14 after alkali burns. On day 14, a histopathological examination was performed to assess morphological change and the infiltration of polymorphonuclear neutrophils (PMNs). The mRNA expression levels of vascular endothelial growth factor (VEGF) and its receptors (VEGFRs), basic fibroblast growth factor (bFGF), matrix metalloproteinases (MMPs), interleukin-1α, 1ß, 6 (IL-1α, IL-1ß, IL-6) were analyzed using real-time quantitative polymerase chain reaction. The expression of MMP-2 and MMP-9 proteins was determined by gelatin zymography. In addition, enzyme-linked immunosorbent assay was used to analyze the protein levels of VEGFR1, VEGFR2, IL-1ß and IL-6. Minocycline at a dose of 60 mg/kg or 30 mg/kg significantly enhanced the recovery of the corneal epithelial defects more than PBS did. There were significant decreases of corneal neovascularization in the group of high-dosage minocycline compared with the control group at all checkpoints. On day 14, the infiltrated PMNs was reduced, and the mRNA expression of VEGFR1, VEGFR2, bFGF, IL-1ß, IL-6, MMP-2, MMP-9, -13 as well as the protein expression of VEGFR2, MMP-2, -9, IL-1ß, IL-6 in the corneas were down-regulated with the use of 60 mg/kg minocycline twice a day. Our results showed that the intraperitoneal injection of minocycline (60 mg/kg b.i.d.) can significantly inhibit alkali burn-induced corneal neovascularization in mice, possibly by accelerating corneal wound healing and by reducing the production of angiogenic factors, inflammatory cytokines and MMPs.

An optical flow-based integrated navigation system inspired by insect vision.

Some insects use optic flow (OF) to perform their navigational tasks perfectly. Learning from insects' OF navigation strategies, this article proposes a bio-inspired integrated navigation system based on OF. The integrated navigation system is composed of an OF navigation system (OFNS) and an OF aided navigation system (OFAN). The OFNS uses a simple OF method to measure motion at each step along a path. The position information is then obtained by path integration. However, path integration leads to cumulative position errors which increase rapidly with time. To overcome this problem, the OFAN is employed to assist the OFNS in estimating and correcting these cumulative errors. The OFAN adopts an OF-based Kalman filter (KF) to continuously estimate the position errors. Moreover, based on the OF technique used in the OFNS, we develop a new OF method employed by the OFAN to generate the measurement input of the OF-based KF. As a result, both the OFNS and the OFAN in our integrated navigation system are derived from the same OF method so that they share input signals and some operations. The proposed integrated navigation system can provide accurate position information without interference from cumulative errors yet doing so with low computational effort. Simulations and comparisons have demonstrated its efficiency.

[Nitrate leaching characteristics of wheat-corn rotation farmland in Guanzhong area of Shaanxi].

By using in situ leaching device, a field experiment was conducted to study the effects of nitrogen fertilization rate and straw mulching on the nitrate leaching at 90 cm soil depth, nitrate accumulation in soil profile (0-100 cm), crop yield, and nitrogen balance of wheat-corn rotation farmland in Guanzhong area of Shaanxi. Six treatments were installed, i. e., no fertilization (N1, 0 kg x hm(-2) x a(-1)), conventional fertilization (N2, 471 kg x hm(-2) x a(-1)), recommended fertilization (N3, 330 kg x hm(-2) x a(-1)), reduced N application (N4, 165 kg x hm(-2) x a(-1)), increased N application (N5, 495 kg x hm(-2) x a(-1)), and recommended fertilization plus straw mulching (N3 + S). The nitrate leaching loss was increased with increasing N fertilization rate. Excessive N fertilization and straw mulching could easily cause nitrate leaching. In treatment N3 + S, the annual NO3(-) -N loss at 90 cm soil depth was the greatest (22.32 kg N x hm(-2)), and the NO3(-) -N loss from N fertilization was 16.44 kg N x hm(-2) x a(-1), being 158.9% higher than that in treatment N3. Nitrate mainly accumulated in 20-60 cm soil layer. When the N application rate was 330 kg N x hm(-2) x a(-1), straw mulching had less effect on the NO3(-) -N distribution in soil profile. No significant difference was observed in the crop yield among the treatments, but reduced N application (N4) tended to decrease the yield. Under our experimental condition, a fertilization rate of 150 kg N x hm(-2) x a(-1) for wheat and 180 kg N x hm(-2) x a(-1) for maize could ensure the crop production and reduce the soil nitrate leaching and accumulation.