Increased electroretinogram a‐wave amplitude after intravitreal bevacizumab injection for neovascular age‐related macular degeneration

Purpose: To assess the effect of bevacizumab (Avastin^®), a vascular endothelial growth factor inhibitor, on retinal function by full‐field electroretinography (ERG) in patients with neovascular age‐related macular degeneration (AMD). Design: A prospective, nonrandomized, controlled interventional clinical trial. Methods: Twelve patients (aged 50?85) with neovascular AMD each received one unilateral intravitreal injection of bevacizumab 1.25 mg/0.05 ml as part of the standard management for choroidal neovascular AMD. Before and 1 month after injection, all patients underwent bilateral full‐field ERG scanning by a masked technician according to the ISCEV protocol, and their wave amplitudes were recorded. Untreated eyes served as controls. Scotopic responses were recorded at four incremental light intensities and photopic responses at two incremental light intensities. Changes in ERG‐amplitude responses were calculated. Repeated‐measures anova was used for data analysis. Results: Mean pre‐ and postinjection differences in a‐wave amplitudes between the incremental light intensities in injected eyes were significantly higher than in controls (15.92 versus 1.33 μV for scotopic responses and 4.97 versus ?1.06 μV for photopic responses; p = 0.057 and p = 0.01, respectively). Mean b‐wave amplitudes in injected eyes were significantly higher than in controls for photopic responses (p = 0.048), but for scotopic responses, the difference between treated and untreated eyes was not significant (p = 0.23). Conclusions: Intravitreally injected bevacizumab improves both rod and cone functioning in patients with neovascular AMD, as demonstrated by the increase in the ERG a‐wave responses of these patients. Other measured ERG parameters yielded no significant photoreceptor toxicity.     

Facilitation of adenoviral wild-type p53-induced apoptotic cell death by overexpression of p33(ING1) in T.Tn human esophageal carcinoma cells

To investigate the effect of p33(ING1) on wild-type p53 gene therapy, T.Tn human esophageal carcinoma cells were stably transfected with p33(ING1) cDNA. Infection with Ad-p53 (recombinant adenovirus containing wild-type p53) into p33-transfected cells reduced cell viability, while infection with empty vector had little effect. This reduced viability was shown to be due to apoptotic cell death by the TUNEL (terminal deoxynucleotidyl transferase-mediated nick end-labeling) assay. Following infection with Ad-p53, levels of p53 were similar in p33-expressing cells and in the parental line. However, levels of p21 and Mdm2 were elevated in p33-transfected cells. Nonetheless, this enhanced expression of Mdm2 appeared to be ineffective in downregulating p53. Transient transfection with mutant Mdm2 prior to Ad-p53 infection provided a significant protection as compared with cells transfected with wild-type Mdm2. These results imply a synergistic effect between p33 and p53 in the induction of apoptosis of human esophageal carcinoma cells. A role for Mdm2 in this synergism is suggested.     

Conditional inactivation of the NBS1 gene in the mouse central nervous system leads to neurodegeneration and disorganization of the visual system

Nijmegen breakage syndrome (NBS) is a genomic instability disease caused by hypomorphic mutations in the NBS1 gene encoding the Nbs1 (nibrin) protein. Nbs1 is a component of the Mre11/Rad50/Nbs1 (MRN) complex that acts as a sensor of double strand breaks (DSBs) in the DNA and is critical for proper activation of the broad cellular response to DSBs. Conditional disruption of the murine ortholog of the human NBS1, Nbs1, in the CNS of mice was previously reported to cause microcephaly, severe cerebellar atrophy and ataxia. Here we report that conditional targeted disruption of the murine NBS1 gene in the CNS results in mal-development, degeneration, disorganization and dysfunction of the murine visual system, especially in the optic nerve. Nbs1 deletion resulted in reduced diameters of Nbs1-CNS-Δ eye and optic nerve. MRI analysis revealed defective white matter development and organization. Nbs1 inactivation altered the morphology and organization of the glial cells. Interestingly, at the age of two-month-old the levels of the axonal guidance molecule semaphorin-3A and its receptor neuropilin-1 were up-regulated in the retina of the mutant mice, a typical injury response. Electroretinogram analysis revealed marked reduction in a- and b-waves, indicative of decreased retinal function. Our study points to a novel role for Nbs1 in the development, organization and function of the visual system.     

An analysis of a multiple biomarker panel to better predict prostate cancer metastasis after radical prostatectomy

A plethora of individual candidate biomarkers for predicting biochemical relapse in localized prostate cancer (PCa) have been proposed. Combined biomarkers may improve prognostication, and ensuring validation against more clinically relevant endpoints are required. The Australian PCa Research Centre NSW has contributed to numerous studies of molecular biomarkers associated with biochemical relapse. In the current study, these biomarkers were re-analyzed for biochemical relapse, metastatic relapse and PCa death with extended follow-up. Biomarkers of significance were then used to develop a combined prognostic model for clinical outcomes and validated in a large independent cohort. The discovery cohort (n = 324) was based on 12 biomarkers with a median follow-up of 16 years. Seven biomarkers were significantly associated with biochemical relapse. Three biomarkers were associated with metastases: AZGP1, Ki67 and PML. Only AZGP1 was associated with PCa death. In their individual and combinational forms, AZGP1 and Ki67 as a dual BM signature was the most robust predictor of metastatic relapse (AUC 0.762). The AZPG1 and Ki67 signature was validated in an independent cohort of 347 PCa patients. The dual BM signature of AZGP1 and Ki67 predicted metastasis in the univariable (HR 7.2, 95% CI, 1.6–32; p = 0.01) and multivariable analysis (HR 5.4, 95% CI, 1.2–25; p = 0.03). The dual biomarker signature marginally improved risk prediction compared to AZGP1 alone (AUC 0.758 versus 0.738, p < 0.001). Our findings indicate that biochemical relapse is not an adequate surrogate for metastasis or PCa death. The dual biomarker signature of AZGP1 and Ki67 offers a small benefit in predicting metastasis over AZGP1 alone.     

A nationwide genetic analysis of inherited retinal diseases in Israel as assessed by the Israeli inherited retinal disease consortium (IIRDC)

Inherited retinal diseases (IRDs) cause visual loss due to dysfunction or progressive degeneration of photoreceptors. These diseases show marked phenotypic and genetic heterogeneity. The Israeli IRD consortium (IIRDC) was established in 2013 with the goal of performing clinical and genetic mapping of the majority of Israeli IRD patients. To date, we recruited 2,420 families including 3,413 individuals with IRDs. On the basis of our estimation, these patients represent approximately 40% of Israeli IRD patients. To the best of our knowledge, this is, by far, the largest reported IRD cohort, and one of the first studies addressing the genetic analysis of IRD patients on a nationwide scale. The most common inheritance pattern in our cohort is autosomal recessive (60% of families). The most common retinal phenotype is retinitis pigmentosa (43%), followed by Stargardt disease and cone/cone–rod dystrophy. We identified the cause of disease in 56% of the families. Overall, 605 distinct mutations were identified, of which 12% represent prevalent founder mutations. The most frequently mutated genes were ABCA4, USH2A, FAM161A, CNGA3, and EYS. The results of this study have important implications for molecular diagnosis, genetic screening, and counseling, as well as for the development of new therapeutic strategies for retinal diseases.     

Experimental studies on nonpenetrating filtration surgery using the CO<Subscript>2</Subscript> laser

Background This study evaluated the use of a CO₂ laser for performing deep sclerectomy in nonpenetrating filtration surgery. Methods Three experimental models were performed: enucleated sheep and cow eyes (n=18) to determine optimal irradiation parameters, live rabbit eyes (n=20) to test feasibility, and cadaver eyes (40 procedures in 20 eyes) to study effects in human eyes tissue. After a half-thickness scleral flap was created, deep sclerectomy was performed by CO₂ laser applications on the scleral bed down to the trabeculo-Descemet’s membrane. Results Fluid percolation was repeatedly achieved without penetration in sheep and cow eyes using scanned laser energy of 5–10 W at a pulse duration of 200 μs and a working distance of 35 cm. In live rabbits, deep sclerectomy was achieved without perforation in 19/20 eyes. Intraocular pressure was significantly decreased on the first postoperative day (10.3±5.1 mmHg lower, on average, than in the nonoperated fellow eye; P<0.001), and this persisted for 21 days. Operations on all cadaver eyes resulted in effective fluid percolation. Penetration of the scleral wall occurred in five cases only after repeated laser applications with high energy. Histologically, a thin sclerocorneal intact wall was demonstrated at the sclerectomy bed. Collateral tissue damage did not extend beyond 100 μm, and adjacent structures remained unharmed. Conclusions CO₂ laser-assisted deep sclerectomy is a feasible and apparently safe procedure. Optomedic Ltd, Or-Yehuda, Israel, which does no longer exists, sponsored this study. Drs. Assia, Barequet and Belkin were paid consultants of Optomedic Ltd. Currently, the IP of the device belongs to OptoTech Ltd, Nazareth, Israel. Dr. Assia is the medical director of OptoTech Ltd.