This study evaluated the long-term visual outcomes of patients in whom at least one eye underwent successful lens-sparing vitrectomy (LSV) for stage 4A retinopathy of prematurity (ROP). A ...retrospective chart review was conducted using the data of 61 eyes of 42 patients with a minimum 4-year follow-up after successful LSV, with or without anti-vascular endothelial growth factor (VEGF) therapy, and whose best-corrected visual acuity (BCVA) was measurable using Landolt rings at the final visit. The mean age at the final follow-up was 10.1 ± 3.3 years. Before LSV, all eyes underwent laser ablation therapy. Twenty eyes (32.8%) with high vascular activity received anti-VEGF therapy before LSV. The mean decimal BCVA at the final follow-up was 0.23 ± 0.26 (range: hand motion to 1.2). Twenty-three eyes (54.1%) had a decimal BCVA of ≥0.4. Among 49 phakic eyes at the final examination, the mean refractive error was -10.1 ± 5.0 D, with 37 eyes (75.5%) having high myopia (>-6.0 D). No significant differences were observed in terms of decimal BCVA and refractive errors between eyes with and without anti-VEGF therapy. Approximately half of the patients had a decimal BCVA of ≥0.4, despite myopic refraction after successful LSV for stage 4A ROP. LSV for stage 4A ROP seemed to be associated with good visual function, despite myopic refraction.
Clinical and experimental observations indicate a role for VEGF secreted by the retinal pigment epithelium (RPE) in the maintenance of the choriocapillaris (CC). VEGF in mice is produced as three ...isoforms, VEGF120, VEGF164, and VEGF188, that differ in their ability to bind heparan sulfate proteoglycan. RPE normally produces the more soluble isoforms, VEGF120 and VEGF164, but virtually no VEGF188, reflecting the fact that molecules secreted by the RPE must diffuse across Bruch's membrane (BrM) to reach the choriocapillaris. To determine the role of RPE-derived soluble VEGF on the choriocapillaris survival, we used mice that produce only VEGF188. VEGF188/188 mice exhibited normal choriocapillaris development. However, beginning at 7 months of age, we observed a progressive degeneration characterized by choriocapillaris atrophy, RPE and BrM abnormalities, culminating in areas of RPE loss and dramatic choroidal remodeling. Increased photoreceptor apoptosis in aged VEGF188/188 mice led to a decline in visual acuity as detected by electroretinogram (ERG). These changes are reminiscent of geographic atrophy (GA) and point to a role for RPE-derived VEGF in the maintenance of the choriocapillaris.
Vascular endothelial growth factor (VEGF) is well known for its role in normal and pathologic neovascularization. However, a growing body of evidence indicates that VEGF also acts on non-vascular ...cells, both developmentally as well as in the adult. In light of the widespread use of systemic and intraocular anti-VEGF therapies for the treatment of angiogenesis associated with tumor growth and wet macular degeneration, systematic investigation of the role of VEGF in the adult retina is critical.
Using immunohistochemistry and Lac-Z reporter mouse lines, we report that VEGF is produced by various cells in the adult mouse retina and that VEGFR2, the primary signaling receptor, is also widely expressed, with strong expression by Müller cells and photoreceptors. Systemic neutralization of VEGF was accomplished in mice by adenoviral expression of sFlt1. After 14 days of VEGF neutralization, there was no effect on the inner and outer retina vasculature, but a significant increase in apoptosis of cells in the inner and outer nuclear layers. By four weeks, the increase in neural cell death was associated with reduced thickness of the inner and outer nuclear layers and a decline in retinal function as measured by electroretinograms. siRNA-based suppression of VEGF expression in a Müller cell line in vitro supports the existence of an autocrine role for VEGF in Müller cell survival. Similarly, the addition of exogenous VEGF to freshly isolated photoreceptor cells and outer-nuclear-layer explants demonstrated VEGF to be highly neuroprotective.
These results indicate an important role for endogenous VEGF in the maintenance and function of adult retina neuronal cells and indicate that anti-VEGF therapies should be administered with caution.
Juglorubin is a natural dye isolated from the culture of Streptomyces sp. 3094, 815, and GW4184. It has been previously synthesized via the biomimetic dimerization of juglomycin C, a plausible ...genetic precursor. In this study, the derivatives of juglorubin, 1-O-acetyljuglorubin dimethyl ester and juglorubin dimethyl ester, were found to exhibit antiviral activity against hepatitis C virus (HCV) without exerting any remarkable cytotoxicity against host Huh-7 cells. They also inhibited liver X receptor α activation and lipid droplet accumulation in Huh-7 cells. These findings suggest that 1-O-acetyljuglorubin dimethyl ester and juglorubin dimethyl ester targeted the host factors required for HCV production.
The relationship between rheological features in the absence of a magnetic field and magnetic response was investigated for κ-carrageenan magnetic hydrogels containing carbonyl iron particles. The ...concentration of carrageenan was varied from 1.0 to 5.0 wt%, while the concentration of carbonyl iron was kept at 70 wt%. The magnetic response revealed that the change in storage modulus Δ
decreased inversely proportional to the carrageenan concentration. A characteristic strain γ
where
' equals to
″ was seen in a strain range of 10
. It was found that Δ
' was inversely proportional to the characteristic stress at γ
. Another characteristic strain γ
where the loss tangent significantly increased was also analyzed. Similar to the behavior of γ
, Δ
' was inversely proportional to γ
. The characteristic stresses at γ
and γ
were distributed at 80-720 Pa and 40-310 Pa, respectively. It was revealed that a giant magnetorheology higher than 1 MPa can be observed when the characteristic stresses at γ
and γ
are below approximately 240 Pa and 110 Pa, respectively.
Congenital protein C deficiency leads to a prothrombotic state that may result in potentially sight- and life-threatening thromboembolic attacks. In this report, we report two cases of infants with ...compound heterozygous protein C deficiency who underwent lensectomies and vitrectomies for the treatment of traction retinal detachments (TRDs).
One two-month-old and one three-month-old female neonates with leukocoria and purpura fulminans received a diagnosis of protein C deficiency and were referred to ophthalmology. In both cases, the right eye had a total retinal detachment that was considered inoperable, while the left eye had a partial TRD for which surgery was performed. Of the two operated eyes, one resulted in a total retinal detachment, while the other eye has remained stable with no retinal detachment progression three months after surgery.
Compound heterozygous congenital protein C deficiency may lead to the rapid development of severe TRDs with poor visual and anatomical prognoses. Early diagnosis and surgery for the treatment of partial TRDs with low disease activity may help prevent progression towards total retinal detachments in these infants.
To determine the role of vascular endothelial growth factor (VEGF) in embryonic eye development and lens differentiation.
Expression of components of the VEGF signaling pathway during lens ...development and in adults was characterized by beta-galactosidase staining of VEGF-LacZ mice, immunohistochemistry, and real-time (q) PCR. Embryonic eyes from wild-type mice and VEGF120/120 mice were analyzed by light microscopy and immunohistochemistry. VEGF function during lens development was analyzed using eye explants treated with VEGF-neutralizing antibody. Direct function of VEGF was demonstrated on the human lens epithelial cell line, HLE-B3.
Embryonic lens epithelium and posterior lens fibers expressed VEGF and VEGFR2. qPCR revealed VEGF164 as the major isoform in embryonic lens. Transgenic mice expressing only VEGF120 (VEGF120/120 mice) showed major defects in eye development, including microphthalmia, failed lens differentiation, and hyperplastic hyaloid vessels. The lens displayed abnormal cell patterning and differentiation associated with altered c-Maf, Prox1, and p57 expression pattern in the anterior epithelium. The number of proliferating epithelial cells was drastically reduced in VEGF120/120 lenses. Altered MIP26 cellular localization and reduced E-cadherin expression in the lens epithelium were observed. VEGF-neutralization led to reduced fiber elongation of eye explants. Exogenous VEGF increased survival and proliferation of HLE-B3 cell in a dose-dependent manner.
Abnormalities in ocular development in VEGF120/120 mice suggest a role for VEGF not only in the formation of ocular vascular beds but also in the differentiation of the lens itself.
A New Breed of Wet-Developable BARC Materials Vyklicky, Libor; Huang, Wu-Song; Popova, Irene ...
Journal of Photopolymer Science and Technology,
01/2009, Letnik:
22, Številka:
1
Journal Article
Odprti dostop
A new family of materials has been developed to serve as a wet-developable bottom antireflective coating (D-BARC) for patterning levels that have a strong need to avoid dry-etch processes for ...BARC-open steps. Such include some implant levels, where dry-etch introduces surface damage that consequently affects the final electrical performance of a device. Other levels that might benefit from all-wet patterning are those using special substrates such as high-k metal-gate (HKMG) levels. Our design of D-BARC materials combines the unique properties of traditional BARC as well as those of a photoresist to deliver a D-BARC solution that is photoimageable in nature. It was found that isotropically developable (i.e., non-imageable) D-BARCs do not provide viable solutions that satisfy the resolution requirements of the current 32 nm technology node and provide the extendibility to future nodes. The optical properties of the D-BARC material are critical for reflectivity control but high optical density can negatively impact the imaging performance of the material. Therefore a balance is needed where the D-BARC is co-optimized with the photoresist as a system, achieves good reflectivity control, residue-free imaging and process gains.
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