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Petah Tikva, Israel

Toledano H.,Tel Aviv University | Muhsinoglu O.,Rabin Medical Center | Luckman J.,Rabin Medical Center | Goldenberg-Cohen N.,Tel Aviv University | Goldenberg-Cohen N.,Krieger Eye Research Laboratory
European Journal of Paediatric Neurology

Background/Purpose The aim of the study was to investigate the incidence of nystagmus at diagnosis in children with optic pathway glioma involving the chiasm and hypothalamus. Methods Twenty-two patients with a measurable optic pathway/hypothalamic glioma (without neurofibromatosis-1) were followed in our center from 2001 to 2013. The medical files were retrospectively reviewed for demographic and clinical findings, and the imaging scans, for tumor characteristics. Results There were 9 boys and 13 girls of mean age 3.5 ± 4.4 years at diagnosis; 15 were aged <2 years. Tumor size ranged from 10 × 6 mm to 62 × 29 mm. Mean duration of follow-up was 8.3 ± 5.4 years. Nystagmus was detected at diagnosis in 10 children (45%), all <2 years old (66.6% of the younger group); no child older than 2 years presented with nystagmus. Nystagmus, once present, did not resolve and continued throughout follow-up. There were no cases of new onset of nystagmus during follow-up in the children in whom it was not detected at diagnosis. Treatment consisted of partial resection/biopsy with/without shunting (n = 13) and chemotherapy (n = 19) with (n = 2) or without adjuvant radiation. Of the 22 children, 6 had a radiographic response to treatment, 8 remained stable, and 8 (all of whom received chemotherapy) showed disease progression despite treatment. Conclusion In conclusion, monocular nystagmus is a more common presenting sign of optic pathway/hypothalamic glioma in children <2 years old than previously estimated. Although subtle, nystagmus has a very narrow differential diagnosis, and its presence should raise suspicions of a chiasmal tumor with prompt referral for imaging. The visual prognosis is moderate to poor. © 2015 European Paediatric Neurology Society. Source

Goldenberg-Cohen N.,Krieger Eye Research Laboratory | Iskovich S.,Center for Stem Cell Research | Askenasy N.,Center for Stem Cell Research
Stem Cells and Development

Small-sized adult bone marrow cells isolated by counterflow centrifugal elutriation and depleted of lineage markers (Fr25lin-) have the capacity to differentiate into insulin-producing cells and stabilize glycemic control. This study assessed competitive migration of syngeneic stem cells to the bone marrow and islets in a murine model of chemical diabetes. VLA-4 is expressed in ∼25% of these cells, whereas CXCR4 is not detected, however, it is transcriptionally upregulated (6-fold). The possibility to enrich stem cells by a bone marrow homing (BM-H) functional assay was assessed in sequential transplants. Fr25lin- cells labeled with PKH26 were grafted into primary myeloablated recipients, and mitotically quiescent Fr25lin-PKHbright cells were sorted from the bone marrow after 2 days. The contribution of bone marrow-homed stem cells was remarkably higher in secondary recipients compared to freshly elutriated cells. The therapeutic efficacy was further increased by omission of irradiation in the secondary recipients, showing a 25-fold enrichment of islet-reconstituting cells by the bone marrow homing assay. Donor cells identified by the green fluorescent protein (GFP) and a genomic marker in sex-mismatched transplants upregulated PDX-1 and produced proinsulin, affirming the capacity of BM-H cells to convert in the injured islets. There was no evidence of transcriptional priming of freshly elutriated subsets to express PDX-1, insulin, and other markers of endocrine progenitors, indicating that the bone marrow harbors stem cells with versatile differentiation capacity. Affinity to the bone marrow can be used to enrich stem cells for pancreatic regeneration, and reciprocally, conditioning reduces the competitive incorporation in the injured islets. © Copyright 2015, Mary Ann Liebert, Inc. 2015. Source

Dratviman-Storobinsky O.,Krieger Eye Research Laboratory
Investigative ophthalmology & visual science

RASSF1A inactivation in uveal melanoma (UM) is common and methylation-induced. We investigated the effect of RASSF1A re-expression on the UM phenotype in vivo and in vitro. The phenotypic effect of methylation-induced inactivation of RASSF1A in UM was explored using a stable RASSF1A-expressing UM-15 clone. RASSF1A expression was assessed using QRT-PCR. Proliferation was evaluated in vitro using MTT assays. Additionally, athymic NOD/SCID mice were injected subcutaneously or intraocularly with RASSF1A-expressing and -non-expressing UM-15 clones, and euthanized when tumors reached a volume of 1500 mm(3), or at 56 or 46 days, respectively. Tumor tissues, eyes, and livers were analyzed histologically. In vitro analysis confirmed the lack of RASSF1A expression and full methylation of the RASSF1A promoter region in the UM-15 cell line, which was reversible following treatment with 5-Aza-2-deoxycytidine. Cells expressing exogenous RASSF1A showed slower proliferation than controls and regained sensitivity to cisplatin. Compared to mice injected with control cells, mice treated with UM-15 cells expressing exogenous RASSF1A did not acquire intraocular tumors, and their subcutaneous tumors were relatively delayed and small. Neither group had liver metastases. UM cells reduced tumorigenicity in the presence of activated RASSF1A. RASSF1A apparently has an important role in the development of UM, and its reactivation might be applied in the development of new treatments. Source

Goldenberg-Cohen N.,Krieger Eye Research Laboratory | Goldenberg-Cohen N.,Tel Aviv University | Banin E.,Hebrew University of Jerusalem | Zalzstein Y.,Raphael Recanati Genetic Institute | And 8 more authors.
Molecular Vision

Purpose: Retinitis pigmentosa (RP), the most genetically heterogeneous disorder in humans, actually represents a group of pigmentary retinopathies characterized by night blindness followed by visual-field loss. RP can appear as either syndromic or nonsyndromic. One of the most common forms of syndromic RP is Usher syndrome, characterized by the combination of RP, hearing loss, and vestibular dysfunction. Methods: The underlying cause of the appearance of syndromic and nonsyndromic RP in three siblings from a consanguineous Israeli Muslim Arab family was studied with whole-genome homozygosity mapping followed by whole exome sequencing. Results: The family was found to segregate novel mutations of two different genes: myosin VIIA (MYO7A), which causes type 1 Usher syndrome, and phosphodiesterase 6B, cyclic guanosine monophosphate-specific, rod, beta (PDE6B), which causes nonsyndromic RP. One affected child was homozygous for both mutations. Since the retinal phenotype seen in this patient results from overlapping pathologies, one might expect to find severe retinal degeneration. Indeed, he was diagnosed with RP based on an abnormal electroretinogram (ERG) at a young age (9 months). However, this early diagnosis may be biased, as two of his older siblings had already been diagnosed, leading to increased awareness. At the age of 32 months, he had relatively good vision with normal visual fields. Further testing of visual function and structure at different ages in the three siblings is needed to determine whether the two RP-causing genes mutated in this youngest sibling confer increased disease severity. Conclusions: This report further supports the genetic heterogeneity of RP, and demonstrates how consanguinity could increase intrafamilial clustering of multiple hereditary diseases. Moreover, this report provides a unique opportunity to study the clinical implications of the coexistence of pathogenic mutations in two RP-causative genes in a human patient. © 2013 Molecular Vision. Source

Rappoport D.,Hebrew University of Jerusalem | Goldenberg-Cohen N.,Krieger Eye Research Laboratory | Goldenberg-Cohen N.,Pediatric Ophthalmology Unit | Goldenberg-Cohen N.,Tel Aviv University | And 2 more authors.
Journal of Neuro-Ophthalmology

Parainfectious optic neuritis may appear at any age. The aim of our report was to compare the clinical manifestations and outcomes of this form of optic neuritis between children and adults. METHODS:: The study sample consisted of all patients diagnosed with parainfectious optic neuritis evaluated by 2 neuro-ophthalmology services between 2005 and 2012. Data were collected retrospectively from the medical files. Findings were compared between patients aged 0-18 years and 19 years or older. RESULTS:: Ten children (50% female) and 8 adults (50% female) met the study criteria. Mean duration of follow-up was 29.4 months (range, 2-72 months) in the pediatric group and 14.2 months (range, 5-80 months) in the adult group. Respective rates of bilateral disease were 50% and 38%, and all patients had optic disc swelling. The associated pathogen was identified in 60% of the pediatric group, mainly Mycoplasma pneumoniae, and 75% of the adult group, in which no microorganism predominated. The interval from the febrile illness to symptom onset was 6 days (range, 1-14 days) in the pediatric group and 19.5 days (range, 14-30 days) in the adult group. Acute disseminated encephalomyelitis (ADEM) was diagnosed in 40% (4/10) of the children and none of the adults. Final visual outcome was 20/30 or better in all patients. There was a higher frequency of bilateral disease in prepubescent vs postpubescent children. CONCLUSIONS:: Parainfectious optic neuritis is associated with a favorable visual prognosis regardless of age. Children tend to manifest visual symptoms sooner after the antecedent infectious illness and more often bilaterally and in conjunction with ADEM. The causative agent is isolated less frequently in children compared with adults. © 2014 by North American Neuro-Ophthalmology Society. Source

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