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PurposeTo investigate the possibility of collagen type VIII α2 (COL8A2) as a potential susceptibility gene for Korean patients with Fuchs' corneal dystrophy (FECD), we performed mutation screening of the COL8A2 gene.MethodsA total of 25 FECD patients were screened, including 15 patients from six pedigrees with early onset FECD and an additional 10 unrelated patients, all of Korean ancestry. Seventy-three control individuals without corneal disease were selected from the general population. PCR—SSCP and direct sequencing were used to screen genetic variations in COL8A2. The pathogenic impact of these sequence variants was evaluated through the SIFT and PolyPhen algorithms.ResultsWe have identified a novel heterozygous mutation, Q455V, in exon 2 of COL8A2. All patients of Korean pedigrees with FECD had the Q455V mutation, and two out of nine unrelated cases also had this mutation. But it was not present in unaffected individuals from these pedigrees or from control groups. Two heterozygous missense mutations, R155Q and T502M, were also observed, but, they showed no significant difference between FECD patients and controls. The allele frequencies of A35A and G495G, which were synonymous substitutions, were significantly associated with FECD. Both Q455V and T502M were predicted as deleterious mutations by computational methods using PolyPhen and SIFT.ConclusionsOur data constitute the first report of a heterozygous Q455V mutation of the COL8A2 gene in Korean patients with FECD. Q455V may be the causative defect in the development and progression of Korean FECD patients.Eye (2009) 23, 895–903; doi:10.1038/eye.2008.116; published online 9 May 2008 [ABSTRACT FROM AUTHOR]

In this study, chlorine decay experiments were conducted for the raw water from Nakdong River that is treated by Chilseo Water Treatment Plant (CWTP) situated in Haman, Korea as well as the effluents from sand and granular activated carbon (GAC) filters of CWTP and fitted using a chlorine decay model. The model estimated the fast and slow reacting nitrogenous as well as organic/inorganic compounds that were present in the water. It was found that the chlorine demand due to fast and slow reacting (FRA and SRA) organic/inorganic substances was not reduced significantly by sand as well as GAC filters. However, the treated effluents from those filters contained FRA and SRA that are less reactive and had small reaction rate constants. For the effluents from microfiltration, ultrafiltration, and nanofiltration the chlorine demand because FRA and SRA were further reduced but the reaction rate constants were larger compared to those of sand and GAC filter effluents. This has implications in the formation of disinfection by products (DBPs). If DBPs are assumed to form due to the interactions between chlorine and SRA, then it is possible that the DBP formation potential in the effluents from membrane filtrations could be higher than that in the effluents from granular media filters.

Purpose: To investigate the genetic association between unrelated Korean keratoconus patients and interleukin 1 alpha (IL1A), interleukin 1 beta (IL1B), and IL1 receptor antagonist (IL1RN) gene polymorphisms., Methods: We investigated the association between IL1A (rs1800587, rs2071376, and rs17561), IL1B (rs1143627, rs16944, rs1143634, and rs1143633), and IL1RN (rs419598, rs423904, rs424078, and rs315952, variable number tandem repeat [VNTR]) polymorphisms in 100 unrelated Korean keratoconus patients. One hundred control individuals without any corneal disease were selected from the general population. Polymerase chain reaction (PCR) - restriction fragment length polymorphism (RFLP) analysis and direct sequencing were used to screen for genetic variations in the IL1 gene cluster. Haplotypes for the IL1 gene cluster were constructed using Haploview version 4.0., Results: We analyzed a total of 12 polymorphic sites in the IL1 gene cluster. Among them, the -511 (rs16944) and -31 (rs1143627) positions in the promoter region of IL1B were significantly different between patient and control groups. The C allele of rs16944 (-511C>T, p=0.022, odds ratio of risk [OR]=1.46, 95% confidence intervals [CI] 0.94<2.27) and the T allele of rs1143627 (-31T>C, p=0.025, OR=1.43, 95% CI 0.92<2.22) were associated with a significantly increased risk of keratoconus in Korean patients. Linkage of the two alleles, -31*C and -511*T, was associated with an increased risk for keratoconus with OR=2.38 (p=0.012, 95% CI=1.116-5.046). The *C/*A genotype of rs2071376 in IL1A intron 6 was significantly different between the keratoconus patients and control subjects (p=0.034, OR=0.59, 95% CI 0.32<1.11). Other polymorphisms did not show an association with keratoconus risk., Conclusions: This is the first report of IL1 gene cluster mutation screening in Korean keratoconus patients. Significant differences in allelic frequency of IL1B between keratoconus patients and the control group suggest that IL1B polymorphisms may play a role in the susceptibility of unrelated Koreans to develop keratoconus.

Purpose: Mutations in the BIGH3 gene on chromosome 5q31 cause four distinct autosomal dominant corneal dystrophies. We sought to determine whether the BIGH3 gene mutation was responsible for corneal dystrophy in Korean patients., Methods: Polymerase chain reaction single strand conformational polymorphism (PCR-SSCP) analysis was performed with the DNA from patients and healthy individuals. We sequenced the PCR products with the aberrant SSCP pattern to identify the mutation. Mutant-specific reverse primers were used to screen genomic DNA for the identified mutations., Results: We identified mutations R124C in the CDL1 family and R124H in four families with a granular dystrophy. We identified our granular dystrophy to be Avellino corneal dystrophy (ACD). Eighteen of 20 patients with a granular dystrophy contained the same R124H mutation, indicating that mutation R124H was very common in Korean patients with ACD. During this study, we identified a new polymorphism (T1667C, F540F)., Conclusions: This is the first report of mutations found in the BIGH3 gene in Korean families with corneal dystrophy. We report that the majority (90%) of ACD patients in Korea carry the R124H mutation. Mutant-specific reverse primers can be used to screen efficiently for CDL1 and ACD.

We investigated the kinetics of multiple cytokines and inducible nitric oxide synthase (iNOS) in experimental uveitis induced by bovine melanin protein (BMP) for the proper treatment of uveitis. Experimental uveitis was induced in male Lewis rats by injection of BMP. The levels of various inflammatory cytokines and iNOS mRNAs were semiquantified by the reverse-transcriptase reaction followed by PCR. The uveitis was started to develop at approximately day 14 and peaked around 21 days after immunization. The signs of uveitis disappeared by 4 weeks after immunization. When the inflammation was severest, TNF-alpha, IL-1alpha, IL-10, IFN-gamma and iNOS mRNA increased to their peak, which varied with the degree of induction and different time course. We concluded that both cytokines and iNOS might modulate the inflammation at different states of experimental melanin-protein-induced uveitis. Their combination will be necessary for an effective treatment of inflammation., (Copyright 2001 S. Karger AG, Basel)

Complestatin, a peptide derived from Streptomyces, was found to protect cultured cortical neurons from excitotoxicity induced by N-methyl-D-aspartate (NMDA), alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), or kainate. This neuroprotective behavior of complestatin was attributed to a blockade of Ca2+ ion entry and accumulation, after the activation of NMDA and AMPA/kainate receptors. Complestatin reversibly interfered with NMDA- and AMPA-mediated excitatory synaptic transmission. Complestatin also protected cortical neurons from prolonged deprivation of oxygen and glucose, more effectively than combined antagonists of NMDA and AMPA/kainate receptors. Neurotoxicity, evolving within 1 to 2 days after continuous exposure to combined NMDA and AMPA/kainate antagonists, was not observed in cortical cell cultures that were exposed to complestatin. Finally, complestatin dose dependently prevented neuronal death evolving within the inner nuclear and ganglion cell layers, after transient retinal ischemia. We conclude that complestatin possesses novel pharmacological properties that effectively prevent excitotoxicity under certain pathological conditions.

Synaptically released Zn2+ ions enter into neurons primarily through voltage-gated Ca2+ channels (VGCC) or N-methyl-d-aspartate (NMDA) receptors, which can mediate pathological neuronal death. We studied the possibility (and underlying mechanisms) that aspirin, known to prevent NMDA neurotoxicity, would also attenuate Zn2+ neurotoxicity. Administration of 3 to 10 mM aspirin, in cortical cell cultures, attenuated the evolution of neuronal death following exposure to 300 microM Zn2+ for 30 min. This neuroprotective effect of aspirin was attributable to the prevention of Zn2+ ion entry. Aspirin interfered with inward currents and an increase in [Ca2+]i through VGCC and selective binding of omega-conotoxin, sensitive to N-type Ca2+ channel. The omega-conotoxins GVIA or MVIIC, the selective inhibitors of N-type Ca2+ channels, attenuated Zn2+ neurotoxicity. Aspirin derivatives lacking the carboxyl acid group did not reduce Zn2+ neurotoxicity. The present findings suggest that aspirin prevents Zn2+-mediated neuronal death by interfering with VGCC, and its action specifically requires the carboxyl acid group., (Copyright 2001 Academic Press.)

Purpose: To evaluate the expression of vascular endothelial growth factor (VEGF) in pterygium and investigate the interrelationships between VEGF and nitric oxide (NO) in the development of pterygia., Methods: Specimens of normal conjunctiva acquired incidentally to conjunctival transplantation during pterygium and strabismus surgery and the excised pterygium were used in this study. Cryopreserved tissue specimens consisting of normal conjunctiva and pterygium were used to study the expression of VEGF and inducible NO synthetase (iNOS), using immunohistochemistry. For confirmation of NOS activity, reduced nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase staining was done. Enzyme-linked immunosorbent assay (ELISA) for detection and quantification of VEGF was performed., Results: Expression of VEGF and iNOS was strongly revealed mainly in the epithelium of the head portions of pterygial specimens, although not in the epithelium of conjunctival ones. Pterygial epithelium was stained with NADPH diaphorase, confirming NOS activity. ELISA showed a greater amount of VEGF in pterygium (11.7 +/- 2.1 pg/mg) compared with normal conjunctiva (4 +/- 0.47 pg/mg) ( p < 0.05)., Conclusion: These data are the first to demonstrate that VEGF and NO may play an important role in the development of pterygium and to identify VEGF and NO in the epithelium of pterygium. We hypothesize that environmental stress, such as ultraviolet irradiation and local inflammation stimulate the elaboration of NO and VEGF, resulting in the conjunctival fibrovascular ingrowth characteristic of pterygium.

Transforming growth factor-beta (TGF-beta) is known to be a causative factor in pathological fibrosis and the metastasis of cancer cells, through effects on molecules of the extracellular matrix (ECM). We evaluated the influence of TGF-beta(1) on the gene expression of matrix metalloproteinase-2 (MMP-2) in lens epithelial cells (LECs). The results showed that TGF-beta(1) induced the expression of mRNA for MMP-2 in LECs. Subsequently, in order to examine the role of MMP-2, we overexpressed MMP-2 in LECs by stable transfection. The MMP-2-overexpressing LECs showed typical indicators of a myofibroblast-like cell phenotype, such as multiple layers of cells, elongated morphology, and expression of alpha-smooth muscle actin. We also showed that an MMP inhibitor blocked the TGF-beta(1)-induced morphological change in LECs. These results demonstrate that MMP-2 plays a role in the transformation of LECs, which has implications for the pathological fibrosis of these cells.

Connective tissue growth factor (CTGF) has recently been described as a fibrogenic factor and is greatly induced by various extracellular stimuli, such as transforming growth factor-beta (TGF-beta), dexamethasone, and serotonin. CTGF induces collagen type I and fibronectin, and the deposition of such molecules leads to fibrotic disease in many tissues. Intracellular reactive oxygen species (ROS) are generated by extracellular stress conditions and are produced as by-products of cellular metabolism. Imbalanced cellular redox status is a potent pathogenic factor that leads to various degenerative diseases, including tissue fibrosis. Since CTGF is believed to play a crucial role in fibrotic disease formation in many tissues, we examined the role of ROS in CTGF gene expression in human lens epithelial cell line B3. The results showed that CTGF was induced by reactive oxygen species such as hydrogen peroxide and hydroxyl radicals. Next, we examined whether CTGF induction by ROS is via newly synthesized TGF-beta. The results showed that ROS directly induced CTGF mRNA not via the increased TGF-beta synthesis or activation. Next, we treated AG490, which is the well-known inhibitor of Janus kinase (JAK), with hydrogen peroxide. AG490 abrogated the CTGF induction by ROS in a dose-dependent manner. The results suggest that JAK-2/-3 seems to be involved in the enhanced CTGF mRNA expression by hydrogen peroxide. In this report, we present that hydrogen peroxide is a novel inducer of CTGF gene expression and that JAK-2/-3 activation seems to play a role in CTGF induction., (Copyright 2001 Academic Press.)

Integrins represent the main cell surface receptors that mediate cell-matrix and cell-cell interactions. They play critical roles in adhesion, migration, morphogenesis, and the differentiation of several cell types. Previous studies have demonstrated that members of the fibroblast growth factor (FGF)-2, transforming growth factor (TGF)-beta(1), and insulin growth factor (IGF)-1 play important roles in lens biology. In particularly, TGF-beta(1) appears to play a key role in extracellular matrix production, cell proliferation, and cell differentiation of lens epithelial cells. In this study we investigated the effects of FGF-2, TGF-beta(1), and IGF-1 on the modulation of integrin receptors using lens epithelial cell lines (HLE B-3 and alphaTN-4) and lens explants. We found that the expression of integrin alpha6 is downregulated by TGF-beta(1), but is not responsive to FGF-2 or IGF-1. The promoter activity of the integrin alpha6 gene decreased upon TGF-beta(1) treatment in a transient transfection assay, and flow cytometric analysis demonstrated the reduced expression of integrin alpha6 by TGF-beta(1), whereas significant changes were not observed in the level of integrin alpha6 after the addition of FGF-2. These findings suggest that the reduced expression of integrin alpha6 caused by TGF-beta(1) might play a role in the activation of the cell cycle genes required during the fiber differentiation of the lens., (Copyright 2001 Academic Press.)

Purpose: To evaluate the inhibitory effect of the farnesyl transferase inhibitor 2'-O-benzoylcinnamaldehyde (CB 2'-ph) on proliferation and migration of vascular endothelial cells., Methods: Bovine lens epithelial cells, bovine corneal endothelial cells, bovine keratocytes, bovine aortic endothelial cells (BAECs) and human umbilical vein endothelial cells (HUVECs) were treated with CB 2'-ph to determine its cell type specificity and antiproliferative effect. For inhibition of vascular endothelial cell growth factor (VEGF)- or basic fibroblast growth factor (bFGF)-induced proliferation of HUVECs, these cells were treated with various concentrations of CB 2'-ph. To assess the proliferation, MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide) assay was used. The migration assay was also performed to determine the effect of CB 2'-ph on HUVECs. The distance of HUVEC outgrowth was measured from the scraped edge of a monolayer after treatment with CB 2'-ph concentrations of 0, 1.5 and 2.5 microg/ml for 24, 48 and 72 h., Results: The CB 2'-ph had an inhibitory effect on all tested types of cell proliferation but only HUVEC and BAEC proliferation was specifically inhibited in a dose-dependent manner. In addition, CB 2'-ph inhibited VEGF- or bFGF-induced proliferation and migration of HUVECs in a dose-dependent manner., Conclusions: These results indicate that CB 2'-ph, a farnesyl transferase inhibitor is thought to be an effective inhibitor of vascular endothelial cell proliferation and migration., (Copyright 2001 S. Karger AG, Basel.)

The extended exposure of proteins to reducing sugars leads to nonenzymatic glycation with the accumulation of advanced glycation end products (AGEs). Long-lived proteins, such as collagen and crystallins, are subjected to this modification, and are implicated as causal factors in several diseases including diabetic complications, cataracts, and arteriosclerosis. One means through which AGEs modulate cellular interactions is via binding to specific receptors. In the current study, the existence of AGEs in human anterior polar lens capsules of cataracts was confirmed using a combination of dot-immunoblot and fluorescent detection. Human lens epithelial cells (LECs) attached to anterior lens capsules expressed mRNA for the receptor for AGEs (RAGE). The interaction of LECs with AGEs using bovine lens epithelial explants demonstrated that AGEs induced mRNAs and proteins of fibronectin, collagen type I, aberrant extracellular matrix proteins, and alpha-SMA, a specific marker for myofibroblastic cells. These findings suggest that AGEs may alter cellular functions which induce mRNAs and proteins associated with fibrosis in LECs., (Copyright 2000 Academic Press.)

Purpose: In anterior polar cataracts and the fibrosis that can occur after cataract surgery, lens epithelial cells synthesize abundant extracellular matrix molecules and transdifferentiate into myofibroblast-like cells. Transforming growth factor (TGF)-beta has been implicated as a key player in these cataractous changes. The purpose of this study was to determine whether the TGF-beta-inducible gene h3 (betaig-h3) is expressed in lens epithelial cells from patients with anterior polar cataracts and to test whether betaig-h3 is induced by TGF-beta in cultured lens epithelial cells., Methods: Lens epithelial cells attached to the anterior capsules of human cataractous lenses and noncataractous lenses were examined for the expression of betaig-h3 mRNA and protein using reverse transcription-polymerase chain reaction and immunohistochemical analyses. The effect of TGF-beta on betaig-h3 gene expression was also tested in human lens epithelial B-3 cells using Northern and Western blot analyses., Results: betaig-h3 mRNA was not detected in lens epithelial cells from patients with clear lenses or patients with nuclear cataracts. Significant expression of mRNA for betaig-h3 was observed in lens epithelial cells from patients with anterior polar cataracts. Immunohistochemical analysis using anti-betaig-h3 antiserum indicated that betaig-h3 protein was present within the subcapsular plaques of anterior polar cataracts. Treatment of human lens epithelial B-3 cells with TGF-beta1 led to an increase in betaig-h3 mRNA and the secretion of betaig-h3 protein into the culture medium., Conclusions: betaig-h3 may serve as a marker for anterior polar cataracts in addition to previously known proteins, fibronectin, type I collagen, and alpha-smooth muscle actin. The functions of this protein in lens pathology need to be further investigated.

Purpose: To determine whether the delivery of the SV40 large T-antigen is a feasible method for transiently inducing proliferation of corneal endothelial cells., Methods: Liposome-mediated delivery of proteins into bovine corneal endothelial cells (BCEC) was utilized in this study. Initially, beta-galactosidase was used as a marker protein for cell delivery and cells were assayed colorimetrically for beta-galactosidase activity. Subsequently, SV40 large T-antigen protein was introduced into BCEC and positive cells were identified by immunohistochemistry 24 hours after liposome-protein treatment. Quiescent BCECs were double-labeled using BrdU as a measure of de novo DNA synthesis and the SV40 large T-antigen was detected by standard immunohistochemical methods., Results: Beta-galactosidase or SV40 large T antigen were introduced into BCECs using liposome transfer methods. The transfer efficiency of beta-galactosidase was > 30% of the cells. SV40 large T antigen was successfully introduced and was localized to the nuclei of BCECs. The treatment of quiescent BCECs with large T antigen caused an increase in BrdU incorporation. Co-labeling confirmed that only cells containing SV40 large T antigen were positive for de novo DNA synthesis., Conclusions: This study demonstrates that proteins can be inserted directly into corneal endothelial cells. In the case of the SV40 large T-antigen, the protein localized to the nucleus and maintained its bioactivity by inducing DNA synthesis. This finding suggests that liposome-mediated delivery of transforming proteins could be a method to transiently induce corneal endothelial cell proliferation.

Purpose: To determine the levels of mRNAs encoding markers of fibrosis in lens epithelial cells (LECs) from patients with anterior polar cataracts and to test whether transforming growth factor (TGF)-beta enhances the expression of mRNAs for mesenchymal markers in LECs., Methods: LECs attached to the anterior capsules of patients with nuclear or anterior polar cataracts were analyzed by reverse transcription-polymerase chain reaction (RT-PCR) for the expression of mRNAs encoding pathologic extracellular matrix proteins, a marker of myofibroblast transformation, growth factors, and growth factor receptors, and by western blot analysis for the proteins encoded by these mRNAs. Bovine lens epithelial explants and intact rabbit lenses cultured with or without TGF-beta1 were also subjected to RT-PCR and western blot analysis., Results: The levels of fibronectin, type I collagen, and alpha-smooth muscle actin (SMA) mRNAs were higher in LECs from patients with anterior polar cataracts than in those from patients with nuclear cataracts. Expression of mRNAs for TGF-beta1, TGF-beta2, TGF-beta receptor type II, and connective tissue growth factor (CTGF) was significantly greater in anterior polar type than in nuclear type cataracts. In contrast, expression of mRNAs for epidermal growth factor (EGF), epidermal growth factor receptor (EGFR), fibroblast growth factor (FGF)-2, and FGF receptor-1 was similar in LECs from the two types of cataracts. TGF-beta1 markedly increased the levels of fibronectin, type I collagen, and alpha-SMA mRNA in bovine lens epithelial explants and intact rabbit lenses., Conclusions: This is the first finding showing altered mRNA expression in LECs from anterior polar cataracts. Enhanced expression of TGF-beta and the TGF-beta receptor suggests that TGF-beta derived from LECs may function in an autocrine fashion as the prime mediator of transdifferentiation and pathogenesis in human LECs. Elevated levels of CTGF mRNA suggest that this growth factor may play a role in the increased deposition of extracellular matrix in metaplastic LECs.

Purpose: The loss of corneal endothelial cells associated with aging and possibly other causes has been speculated to be related to exposure to reactive oxygen species (ROS). The current study was conducted to investigate, by use of photosensitizers, the underlying mechanisms involved in the death of bovine corneal endothelial cells (BCENs) caused by ROS., Methods: BCEN cells in primary culture were treated with a photosensitizer (riboflavin or rose bengal) with light exposure. The patterns of cell damage and death were assessed using an acridine orange-ethidium bromide differential staining method, TdT-mediated dUTP nick-end labeling (TUNEL) assay, and transmission electron microscopy. The cytotoxicity was assayed by mitochondrial function using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) testing. Antioxidants, including catalase, L-histidine, salicylic acid, and superoxide dismutase, were used to determine the types of ROS involved. Activation of nuclear factor (NF)-kappaB was examined by fluorescent immunocytochemistry with anti-p65 antibody., Results: Light-irradiated riboflavin or rose bengal resulted in a significant decrease in viability of BCEN cells. Chromosomal condensation and fragmentation were observed in apoptotic cells, and membrane lysis and damage of cell ultrastructures were observed in necrotic cells. Riboflavin induced apoptosis at 30 minutes and thereafter and induced necrosis after 2 hours. Rose bengal was shown to cause similar effects within half the time required for the effects of riboflavin. Catalase and salicylic acid were found to provide protection for BCENs from cytotoxic effects of riboflavin, and L-histidine was found to protect BCENs from cytotoxicity induced by rose bengal. Kinetic studies using immunocytochemistry showed that NF-kappaB was translocated into the nucleus within 15 minutes and 30 minutes after treatment with rose bengal and riboflavin, respectively., Conclusions: The cytotoxic effects of photo-irradiated riboflavin and rose bengal are shown to be mediated by two distinct but parallel pathways, one leading to apoptosis and the other to necrosis. Possible involvement of NF-kappaB in cell death is suggested. These findings provide potential leads for future investigation into the molecular mechanisms of loss of corneal endothelial cells related to aging, oxidative stress, and possibly other similar causes.

Purpose: Accumulated evidence has shown that apoptosis and necrosis contribute to neuronal death after ischemia. The present study was performed to study the temporal and spatial patterns of neuronal necrosis and apoptosis after ischemia in retina and to outline mechanisms underlying necrosis and apoptosis., Methods: Retinal ischemia was induced by increasing intraocular pressure to a range of 160 mm Hg to 180 mm Hg for 90 minutes in adult rats. The patterns of neuronal cell death were determined using light and electron microscopy and were visualized by TdT-dUTP nick-end labeling (TUNEL). The mRNA expression profile of p53 was examined using reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization histochemistry. Immunohistochemistry was performed using anti-p53, anti-microtubule associated protein-2, and anti-glial fibrillary acidic protein antibodies., Results: Within 4 hours after ischemia, neurons in the inner nuclear cell layer (INL) and ganglion cell layer (GCL) underwent marked necrosis, made apparent by swelling of the cell body and mitochondria, early fenestration of the plasma membrane, and irregularly scattered condensation of nuclear chromatin. After 3 days, the INL and GCL neurons showed further degeneration through apoptosis marked by cell body shrinkage, aggregation, and condensation of nuclear chromatin. Apoptotic neurons were also observed sparsely in the outer nuclear cell layer. Intravitreal injections of MK-801 prevented early neuronal degeneration after ischemia. Of note, mRNA and protein levels of p53, the tumor suppressor gene known to induce apoptosis, were increased in the retinal areas undergoing apoptosis 1 to 3 days after ischemic injury., Conclusions: Ischemia produces the N-methyl-D-aspartate-mediated necrosis and slowly evolving apoptosis of neurons in the retina. The latter may depend on the expression of the p53 proapoptosis gene.

Purpose: To evaluate the effect of poly(methyl methacrylate) (PMMA) and silicone intraocular lenses (IOLs) on posterior capsule opacification (PCO) after cataract surgery., Setting: Kangnam St. Mary's Hospital, Seoul, Korea., Methods: This retrospective study comprised 48 patients (54 eyes) who had neodymium:YAG (Nd:YAG) laser posterior capsulotomy from March 1995 to December 1997. All operations were performed by 1 surgeon using the same technique except for incision method., Results: Mean interval from cataract surgery to Nd:YAG capsulotomy was 31 months in the PMMA group and 15 months in the silicone group. The difference between groups was statistically significant (P = .0002). The ratio of Elschnig pearl to fibrosis type PCO was 16:6 in the PMMA group and 14:18 in the silicone group. Mean total Nd:YAG laser energy used was 256 mJ in the PMMA group and 309 mJ in silicone group. However, the damage caused by the laser was more severe and more common in the silicone group., Conclusion: Silicone IOLs induced PCO faster than PMMA IOLs, with fibrosis the most common type in the silicone group. Precautions should be taken to prevent damage during Nd:YAG laser capsulotomy in eyes with a silicone IOL.

In order to elucidate in vivo neuronal cell death in the retina, and involvement of NF-kappa B in this process, we studied the degeneration of retinal ganglion cells (RGCs) and the activation of NF-kappa B after transection of the optic nerve of adult rat at 5 mm from the eyeball. The morphology of dying ganglion cells in the retinal ganglion cell layer was observed by light and electron microscopy, the activation of NF-kappa B was investigated immunohistochemically. Seven and 14 days post-axotomy, dying cells contained pyknotic nuclei. The death of retinal ganglion cells involved apoptosis, activation of NF-kappa B (p50 and p65) was prominent in a time dependent manner. We observed axotomy-induced NF-kappa B activation, which may mediate apoptosis of retinal ganglion cells.

We present a technique for in situ lens nucleus emulsification using low phaco power and high vacuum, a continuous curvilinear capsulorhexis, and hydrodelineation. Emulsification is done with the phaco tip slanted down 30 or 45 degrees. Cutting and aspiration do not cause an undesirable energy loss. This technique can be combined with the nuclear chopping or divide and conquer methods because of its ability to drill and hold the nucleus. Posterior capsular rupture is prevented because the separated epinucleus acts as a barrier between the nucleus and the cortex. The low power used minimizes the energy transfer to the corneal endothelium. This technique is particularly useful in eyes with brunescent cataract.