Haim Ovadia

Hebrew University of Jerusalem, Yerushalayim, Jerusalem, Israel

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Publications (154)515.36 Total impact

  • [Show abstract] [Hide abstract] ABSTRACT: Objectives: The role of nitric oxide (NO) in modulating the blood-brain barrier (BBB) is not entirely clear. We examined the effect of different NO synthase (NOS) inhibitors and NO donors on the permeability of the BBB in animals with normally functioning brain blood vessels, following disruption by hyperosmotic mannitol and during immune inflammation. Methods: We administered L-NAME, aminoguanidine, S-methyl-thiocitrulline (SMT) and 7-indazole (NOS inhibitors) and NOR-4 (an NO donor) into the cerebral ventricle of rats. Disruption of the BBB was induced by intracarotid injection of mannitol (25%). Experimental autoimmune encephalomyelitis (EAE) was induced by brain homogenate. The extent of disruption was evaluated by Evans blue (2%) dye extravasation. Results: L-NAME (a nonspecific NOS inhibitor) and SMT (a neuronal and endothelial NOS inhibitor) increased mannitol-induced disruption of BBB. This effect was inhibited by NO donors. In animals with a normally functioning BBB, none of these inhibitors or NO donors caused a change in the permeability. 7-indazole (a specific neuronal NOS inhibitor) and aminoguanidine (an inducible NOS inhibitor) had no facilitatory effect on BBB permeability, either alone or in combination with hyperosmotic mannitol. Administration of L-NAME and SMT to rats with EAE significantly aggravated the clinical outcome. In contrast, the administration of NOR-4 diminished clinical signs of EAE. Conclusion: The NOS system does not play a role in BBB permeability in naïve animals. Only endothelial NOS takes part in the facilitation of BBB compromised by mannitol and EAE. Extrinsic NO decreases this facilitatory effect.
    No preview · Article · Dec 2015 · NeuroImmunoModulation
  • [Show abstract] [Hide abstract] ABSTRACT: Background Although antibodies to aquaporin-4(AQP4) are strongly associated with Neuromyelitis optica (NMO), the sole transfer of these antibodies is not sufficient to induce an NMO-like disease in experimental animals and T-cells and complement are also needed. Initial data indicating the presence of T-cell responses to AQP4 in patients with NMO, have beeen recently reported. Objective To evaluate the T-cell responses to specific AQP4 peptides/epitopes in patients with NMO and multiple sclerosis (MS). Methods Peripheral blood mononuclear cells (PBMCs) were obtained from 14 patients fulfilling the criteria for definite NMO and the proliferation responses to one of 15 distinct pentadecapeptides of AQP4, spanning the whole protein (except of its transmembrane parts) were tested by a standard [H3]-thymidine uptake assay and compared with those of 9 healthy controls and 7 MS patients. A cytometric bead array assay (CBA) and flow cytometry were used to evaluate cytokine (IFNγ, IL17, IL2, IL4, IL5, IL10 and TNFα) and chemokine (CXCL8, CCL5, CXCL10, CXCL9, CCL2) secretion by PHA-stimulated PBMCs and AQP4-specific T-cell lines. Results Four main immunodominant epitopes of the AQP4 protein (p137-151, p222-236, p217-231 and the p269-283) were identified in the NMO group. The first two epitopes (assigned as peptides 3 and 9) showed the highest sensitivity (~60% positivity), whereas the latter two (assigned as peptides 8 and 11), the higher specificity. Longitudinal follow up of 5 patients revealed changes in the epitope-specificities during the course of NMO. T-cell lines specific for the AQP4 peptides, produced from NMO patients (but not healthy donors) secreted mainly IL-17 and IL-10 and less IFNγ. Conclusions Our findings indicate that T-cells bearing characteristics of both Th1 and Th17 T-cells and targeting specific immunodominant epitopes of the AQP4 protein might be involved in the pathogenesis of NMO.
    No preview · Article · Dec 2015 · Multiple Sclerosis and Related Disorders
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    [Show abstract] [Hide abstract] ABSTRACT: Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system and is associated with demyelination, neurodegeneration, and sensitivity to oxidative stress. In this work, we administered a nanodroplet formulation of pomegranate seed oil (PSO), denominated Nano-PSO, to mice induced for experimental autoimmune encephalomyelitis (EAE), an established model of MS. PSO comprises high levels of punicic acid, a unique polyunsaturated fatty acid considered as one of the strongest natural antioxidants. We show here that while EAE-induced mice treated with natural PSO presented some reduction in disease burden, this beneficial effect increased significantly when EAE mice were treated with Nano-PSO of specific size nanodroplets at much lower concentrations of the oil. Pathological examinations revealed that Nano-PSO administration dramatically reduced demyelination and oxidation of lipids in the brains of the affected animals, which are hallmarks of this severe neurological disease. We propose that novel formulations of natural antioxidants such as Nano-PSO may be considered for the treatment of patients suffering from demyelinating diseases. On the mechanistic side, our results demonstrate that lipid oxidation may be a seminal feature in both demyelination and neurodegeneration.
    Full-text · Article · Nov 2015 · International Journal of Nanomedicine
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    [Show abstract] [Hide abstract] ABSTRACT: Purpose: It is known that both human conjunctival fibroblasts (HCF) and corneal epithelial (HCE) cells contribute to the inflammatory process in the ocular surface by releasing inflammatory cytokines. In addition, nitric oxide (NO) has an important role in inflammatory responses in the ocular surface. In the present study, we aimed to characterize the capacity of these cells to release nitric oxide in response to cytokines and Lipopolysaccharide (LPS), and show that Alpha-linoleic acid (ALA) inhibits these responses. Methods: HCF, HCE cells, peripheral blood mononuclear cells (PBMCs) and co-culture of HCF and PBMC were treated with different combinations of inflammatory inducers, including interleukin)IL- (6, tumor necrosis factors (TNF)-α, interferon (IFN)- γ and IL-1β and LPS. Nitrite levels were measured in cell supernatants with and without ALA by the Griess reaction test at 24, 48 and 72 h respectively. Expression of nitric oxide synthase 2 (NOS-2) was evaluated by real-time PCR. Results: All cytokine combinations had an inducible effect on nitrite secretion in HCF, PBMC and co-cultured PBMC and HCF, but not in HCE cells. Treatment with a combination of IL-6, LPS, TNF-α, IFN- γ and IL-1β induced the highest nitrite secretion (2.91 fold, P < 0.01) as compared to cells incubated in medium alone. nitrite secretion was reduced by 38.9 % (P < 0.05) after treatment with ALA alone. Co-culturing PBMC with HCF with and without ALA treatment demonstrated similar results in nitrite level as,compared to PBMC alone. In addition, ALA significantly decreased NOS-2 expression in HCF by 48.9 % (P < 0. 001) after 72 h. Conclusions: The decrease in nitrite release and inhibition of NOS-2 expression indicate that ALA may have an anti-inflammatory effect both on HCF and on peripheral immune cells. This indicates that ALA may serve as a potent anti-inflammatory agent in ocular surface inflammation.
    Preview · Article · Oct 2015 · Journal of Inflammation
  • Joseph Weidenfeld · Anna Itzik · Haim Ovadia
    [Show abstract] [Hide abstract] ABSTRACT: Objective: The amygdala (AMG) plays a facilitatory role in the hypothalamic-pituitary-adrenal (HPA) axis. The effect of the AMG on the negative feedback exerted by glucocorticoids (GC) is not clear. We investigated the effect of repeated electrical stimulation of the AMG on the feedback action of GC upon the adrenocortical (AC) response to stressful stimuli. Methods: Rats received electrical stimulation into the central amygdalar nucleus once daily for 4 days. At days 5 and 12 after the onset of stimulation, rats were treated with dexamethasone (Dex) or vehicle and were exposed to either photic or acoustic stress stimuli, and serum corticosterone (CS) was measured. In another group of rats, we measured the binding of Dex to the hippocampal cytosol at 5 and 12 days after the AMG stimulation. Results: At 5 and 12 days after the onset of stimulation or a sham control, stress increased the serum CS level. In the sham group, Dex completely inhibited the CS response, but at 5 days after stimulation, it was significantly less effective in doing this. At day 12, Dex was as effective as in the control group. AMG stimulation delayed the return of CS response to basal levels and caused a significant decrease in the binding capacity of Dex to hippocampal cytosol. Conclusion: Electrical stimulation of the AMG caused a transient impairment of the feedback action of GC upon the stress response. This effect may be due to the decrease in hippocampal corticosteroid receptors. This suggests that the impaired GC feedback caused by AMG stimulation may be involved in the facilitatory effect of the AMG on the function of the AC axis.
    No preview · Article · Sep 2015 · NeuroImmunoModulation
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    [Show abstract] [Hide abstract] ABSTRACT: The present study shows the advantages of liposome-based nano-drugs as a novel strategy of delivering active pharmaceutical ingredients for treatment of neurodegenerative diseases that involve neuroinflammation. We used the most common animal model for multiple sclerosis (MS), mice experimental autoimmune encephalomyelitis (EAE). The main challenges to overcome are the drugs' unfavorable pharmacokinetics and biodistribution, which result in inadequate therapeutic efficacy and in drug toxicity (due to high and repeated dosage). We designed two different liposomal nano-drugs, i.e., nano sterically stabilized liposomes (NSSL), remote loaded with: (a) a "water-soluble" amphipathic weak acid glucocorticosteroid prodrug, methylprednisolone hemisuccinate (MPS) or (b) the amphipathic weak base nitroxide, Tempamine (TMN). For the NSSL-MPS we also compared the effect of passive targeting alone and of active targeting based on short peptide fragments of ApoE or of β-amyloid. Our results clearly show that for NSSL-MPS, active targeting is not superior to passive targeting. For the NSSL-MPS and the NSSL-TMN it was demonstrated that these nano-drugs ameliorate the clinical signs and the pathology of EAE. We have further investigated the MPS nano-drug's therapeutic efficacy and its mechanism of action in both the acute and the adoptive transfer EAE models, as well as optimizing the perfomance of the TMN nano-drug. The highly efficacious anti-inflammatory therapeutic feature of these two nano-drugs meets the criteria of disease-modifying drugs and supports further development and evaluation of these nano-drugs as potential therapeutic agents for diseases with an inflammatory component.
    Full-text · Article · Jul 2015 · PLoS ONE
  • [Show abstract] [Hide abstract] ABSTRACT: Objectives/HypothesisThe objectives of this study were to examine the presence of β-2 transferrin (β2TRNSF) in cerebrospinal fluid (CSF) contaminated in vitro by various bacteria and explore the mechanism (passive or active) responsible for β2TRNSF elimination. Early diagnosis of CSF leakage may change treatment decisions and minimize the risk of meningitis and encephalitis. β2TRNSF is a protein present exclusively in CSF. Its detection is highly useful in cases of CSF leakage, although it has never been examined in the presence of central nervous system infection.Study DesignProspective patient analysis.Methods Sterile CSF drawn from patients was contaminated in vitro with several microorganisms chosen for their ability to cause neurosurgical-related infections: Streptococcus pneumoniae, methicillin-sensitive Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa. β2TRNSF was examined at two time points: following immediate inoculation (t0) and following an overnight incubation (t18) over various bacterial concentrations. Samples of CSF inoculated with S pneumoniae were also examined in the presence of ciprofloxacin. For β2TRNSF analysis we used immunoblotting electrophoresis and enzyme-linked immunosorbent assay (ELISA).ResultsCSF samples collected from nine patients were analyzed. β2TRNSF was not detected following S pneumoniae inoculation at both time points when immunoblotting electrophoresis was used. Quantitative analysis using ELISA demonstrated significant β2TRNSF concentration decrease. The addition of ciprofloxacin led to the same results.ConclusionsCSF leak detection using β2TRNSF may be deceiving in the presence of a S pneumoniae cerebral nervous system infection. A passive process is suggested, as β2TRNSF disappeared either immediately or following incubation with inactive bacteria.Level of EvidenceNA Laryngoscope, 125:556-560, 2015
    No preview · Article · Mar 2015 · The Laryngoscope
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    [Show abstract] [Hide abstract] ABSTRACT: Silencing of O(6)-methylguanine-DNA-methyltransferase (MGMT) in tumors, mainly through promoter methylation, correlates with a better therapeutic response and with increased survival. Therefore, it is conceivable to consider MGMT as a potential therapeutic target for the treatment of cancers. Our previous results demonstrated the pivotal role of NF-kappaB in MGMT expression, mediated mainly through p65/NF-kappaB homodimers. Here we show that the non-canonical NF-KappaB motif (MGMT-kappaB1) within MGMT enhancer is probably the major inducer of MGMT expression following NF-kappaB activation. Thus, in an attempt to attenuate the transcription activity of MGMT in tumors we designed locked nucleic acids (LNA) modified decoy oligonucleotides corresponding to the specific sequence of MGMT-kappaB1 (MGMT-kB1-LODN). Following confirmation of the ability of MGMT-kB1-LODN to interfere with the binding of p65/NF-kappaB to the NF-KappaB motif within MGMT enhancer, the efficacy of the decoy was studied in-vitro and in-vivo. The results of these experiments show that the decoy MGMT-kB1-LODN have a substantial antineoplastic effect when used either in combination with temozolomide or as monotherapy. Our results suggest that MGMT-kB1-LODN may provide a novel strategy for cancer therapy.
    Full-text · Article · Dec 2014 · PLoS ONE
  • [Show abstract] [Hide abstract] ABSTRACT: Background: Screening of putative autoimmune targets in multiple sclerosis (MS) revealed a proportion of patients carrying antibodies (Abs) against KIR4.1, a potassium channel that shares functional properties with AQP4. Both are localized at the perivascular astrocytic processes. Aims: To measure anti-KIR4.1 Abs in the serum of MS and neuromyelitis optica (NMO) patients, and to identify the clinical and laboratory characteristics of patients harboring anti-KIR4.1 Abs. Methods: We measured anti-KIR4.1 Abs in serum, using the peptide KIR4.1 (83-120) enzyme-linked immunosorbent assay (ELISA). Results: Serum levels of anti-KIR4.1 Abs were significantly higher in MS and NMO patients than in healthy controls (HCs); with Abs detected in 21 of 80, 10 of 45, and 2 of 32 individuals, respectively (MS versus HC, p < 0.05). The level of anti-KIR4.1 Abs was significantly higher during MS relapse, versus remission (p = 0.04). The clinical characteristics of our study patients did not vary based on KIR4.1 positivity. Conclusions: Anti-KIR4.1 Abs were found in similar proportions of patients with MS and NMO, at a significantly higher level than observed in HCs; consequently, the presence of Abs does not discriminate between these demyelinating diseases. However, anti-KIR4.1 Ab levels differed in MS patients during relapse and remission; as such, they may represent a marker of disease exacerbation.
    No preview · Article · Nov 2014 · Multiple Sclerosis
  • T. Canello · H. Ovadia · M. Refael · D. Zrihan · T. Siegal · I. Lavon
    [Show abstract] [Hide abstract] ABSTRACT: INTRODUCTION: Silencing of O(6)-methylguanine-DNA-methyltransferase (MGMT) in tumors, correlates with a better therapeutic response and with increased survival. Our previous results demonstrated the pivotal role of NF-kappaB in MGMT expression, mediated mainly through binding of p65/NF-kappaB homodimers to the non-canonical NF-KappaB motif (MGMT-kappaB1) within MGMT enhancer. METHODS AND RESULTS: In an attempt to attenuate the transcription activity of MGMT in tumors we designed locked nucleic acids (LNA) modified decoy oligonucleotides corresponding to the specific sequence of MGMT-kappaB1 (MGMT-kB1-LODN). Following confirmation of the ability of MGMT-kB1-LODN to interfere with the binding of p65/NF-kappaB to MGMT enhancer, the potential of the MGMT-kB1-LODN to enhance cell killing was studied in vitro in two glioma cell lines (T98G and U87) and a melanoma cell line (A375P). All three cell lines manifested a significant enhanced cell killing effect following exposure to temozolomide (TMZ) when first transfected with MGMT-kb1-LODN, and also induced a significant cell killing when administered as monotherapy. These results were confirmed also in-vivo on A375P Melanoma xenografts. Intratumoral (Intralesional - IL) injection of MGMT-kB1-LODN with or without IP injection of TMZ induced significant tumor growth inhibition either as a monotherapy or in combination with TMZ. The long-term effect of MGMT-kB1-LODN monotherapy was evaluated using a repetitive IL injection every 4 to 5 days for 55 days with either MGMT-κB1 LODN or control ODN or vehicle. A significant difference (p < 0.01) in tumor volume was obtained by MGMT-κB1-LODN compared to both control groups. Moreover, two out of the seven mice treated with MGMT-κB1-LODN demonstrated tumor regression by day 55 and no tumor recurrence was observed five months later. CONCLUSION: The results of these experiments show that the MGMT-kB1-LODN has a substantial antineoplastic effect when used either in combination with temozolomide or as monotherapy. Our results suggest that MGMT-kB1-LODN may provide a novel strategy for cancer therapy.
    No preview · Conference Paper · Nov 2014
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    [Show abstract] [Hide abstract] ABSTRACT: Unlabelled: Neurodegenerative diseases generate the accumulation of specific misfolded proteins, such as PrP(Sc) prions or A-beta in Alzheimer's diseases, and share common pathological features, like neuronal death and oxidative damage. To test whether reduced oxidation alters disease manifestation, we treated TgMHu2ME199K mice, modeling for genetic prion disease, with Nano-PSO, a nanodroplet formulation of pomegranate seed oil (PSO). PSO comprises large concentrations of a unique polyunsaturated fatty acid, Punicic acid, among the strongest natural antioxidants. Nano-PSO significantly delayed disease presentation when administered to asymptomatic TgMHu2ME199K mice and postponed disease aggravation in already sick mice. Analysis of brain samples revealed that Nano-PSO treatment did not decrease PrP(Sc) accumulation, but rather reduced lipid oxidation and neuronal loss, indicating a strong neuroprotective effect. We propose that Nano-PSO and alike formulations may be both beneficial and safe enough to be administered for long years to subjects at risk or to those already affected by neurodegenerative conditions. From the clinical editor: This team of authors report that a nanoformulation of pomegranade seed oil, containing high levels of a strong antioxidant, can delay disease onset in a mouse model of genetic prion diseases, and the formulation also indicates a direct neuroprotective effect.
    Full-text · Article · Aug 2014 · Nanomedicine: nanotechnology, biology, and medicine
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    [Show abstract] [Hide abstract] ABSTRACT: Prion diseases, which can manifest by transmissible, sporadic or genetic etiologies, share several common features, such as a fatal neurodegenerative outcome and the aberrant accumulation of proteinase K (PK) resistant PrP forms in the CNS. In infectious prion diseases, such as scrapie in mice, prions first replicate in immune organs, then invade the CNS via ascending peripheral tracts, finally causing death. Accelerated neuroinvasion and death occurs when activated prion infected immune cells infiltrate into the CNS, as is the case for scrapie infected mice induced for Experimental Autoimmune Encephalomyelitis (EAE), a CNS inflammatory insult. To establish whether the immune system plays such a central role also in genetic prion diseases, we induced EAE in TgMHu2ME199 K mice, a line mimicking for late onset genetic Creutzfeldt Jacob disease (gCJD), a human prion disease. We show here that EAE induction of TgMHu2ME199 K mice neither accelerated nor aggravated prion disease manifestation. Concomitantly, we present evidence that PK resistant PrP forms were absent from CNS immune infiltrates, and most surprisingly also from lymph nodes and spleens of TgMHu2ME199 K mice at all ages and stages of disease. These results imply that the mechanism of genetic prion disease differs widely from that of the infectious presentation, and that the conversion of mutant PrPs into PK resistant forms occurs mostly/only in the CNS. If the absence of pathogenic PrP forms form immune organs is also true for gCJD patients, it may suggest their blood is devoid of prion infectivity.
    Full-text · Article · Mar 2014 · Human Molecular Genetics
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    Nir Erdinest · Haim Ovadia · Ran Kormas · Abraham Solomon
    [Show abstract] [Hide abstract] ABSTRACT: This study evaluated the anti-inflammatory effects of Resolvin-D1 (RV-D1) and its mechanism of action in human corneal epithelial (HCE) cells. HCE cells were incubated with different concentrations of RV-D1 for different time periods. Oleic acid (OA) and Dexamethasone (DM) served as negative and positive controls, respectively. Cells were stimulated with polyriboinosinic:polyribocytidylic acids (poly I:C). The protein contents and mRNA expression levels of Tumor necrosis factor-alpha (TNF-alpha), Interleukin (IL)-6, IL-1beta and IL-8 were evaluated with multiplex fluorescent bead immunoassay (FBI) and real time-PCR, respectively. In addition, the expression of inhibitory factor-kappaBalpha (I-kappaBalpha) was evaluated with real time-PCR. The protein level of pro-inflammatory cytokines TNF-alpha, IL-6, IL-1beta and IL-8 significantly increased after stimulation with Poly I:C. RV-D1 treatment at concentration of 1 muM decreased the protein level of TNF-alpha to 20.76 +/- 9.3% (P < 0.05), IL-6 to 43.54 +/- 14.16% (P < 0.001), IL-1beta to 46.73 +/- 15.93% (P > 0.05) and IL-8 to 51.15 +/- 13.01% (P < 0.05) compared with cells stimulated with poly I:C alone. Similarly, the mRNA levels of TNF-alpha, IL-6, IL-1beta and IL-8 were significantly reduced after treatment with RV-D1. A highly significant dose response curve was demonstrated for RV-D1 treated HCE cells for TNF-alpha and IL-1beta.DM treatment decreased the protein content for all of the pro-inflammatory cytokines, similar results were demonstrated at the mRNA level. The anti-inflammatory effects of RV-D1 were similar to those of DM for TNF-alpha, IL-6 and IL-8. RV-D1 may serve as a potent anti-inflammatory agent in ocular surface inflammation, as evaluated in cultured HCE cells. The anti-inflammatory effects of RV-D1 were comparable to those of DM, and were mediated through nuclear factor kappa B (NF-kappaB) signal transduction.
    Preview · Article · Mar 2014 · Journal of Inflammation
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    [Show abstract] [Hide abstract] ABSTRACT: Toll-like receptors (TLRs) are recognized as important contributors to the initiation and modulation of the inflammatory response in the eye. This study investigated the precise expression patterns and functionality of TLRs in human corneal epithelial cells (HCE) and in conjunctival fibroblasts (HCF). The cell surface expression of TLRs 2-4, TLR7 and TLR9 in HCE and HCF was examined by flow cytometry with or without stimulation with lipopolysaccharide (LPS) or polyinosinic:polycytidylic acid (poly I:C). The mRNA expression of the TLRs was determined by real-time PCR. The protein content levels of interleukin (IL)-6, IL-8, IL-1beta and tumor necrosis factor-alpha (TNF-alpha) were measured in HCE and HCF using multiplex fluorescent bead immunoassay (FBI). The surface expression of TLR3 and TLR4 was detected on both HCE and HCF. Following incubation with LPS, the percentage of HCE cells staining for TLR4 decreased from 10.18% to 0.62% (P < 0.001). Incubation with poly I:C lowered the percentage of HCE cells positive for TLR3 from 10.44% to 2.84% (P < 0.001). The mRNA expression of TLRs2, 4, 7 and 9 was detected in HCE only. Activation of HCE with LPS complex elicited protein secretion up to 4.51 +/- 0.85-fold higher levels of IL-6 (P < 0.05), 2.5 +/- 0.36-fold IL-8 (P > 0.05), 4.35 +/- 1.12-fold IL-1beta (P > 0.05) and 29.35 +/- 2.3-fold TNFalpha (P < 0.05) compared to cells incubated in medium. HCF and HCE both express TLRs that are respond to specific ligands by increased cytokines expression. Following activation, the surface expression of TLR3 and TLR4 on HCE is decreased, thus creating a negative feedback loop, mitigating the effect of TLR activation.
    Full-text · Article · Feb 2014 · Journal of Inflammation
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    [Show abstract] [Hide abstract] ABSTRACT: Cerebral malaria is the most severe complication of Plasmodium falciparum infection, and a leading cause of death in children under the age of five in malaria-endemic areas. We report high therapeutic efficacy of a novel formulation of liposome-encapsulated water-soluble glucocorticoid prodrugs, and in particular β-methasone hemisuccinate (BMS), for treatment of experimental cerebral malaria (ECM), using the murine P. berghei ANKA model. BMS is a novel derivative of the potent steroid β-methasone, and was specially synthesized to enable remote loading into nano-sterically stabilized liposomes (nSSL), to form nSSL-BMS. The novel nano-drug, composed of nSSL remote loaded with BMS, dramatically improves drug efficacy and abolishes the high toxicity seen upon administration of free BMS. nSSL-BMS reduces ECM rates in a dose-dependent manner and creates a survival time-window, enabling administration of an antiplasmodial drug, such as artemisone. Administration of artemisone after treatment with the nSSL-BMS results in complete cure. Treatment with BMS leads to lower levels of cerebral inflammation, demonstrated by changes in cytokines, chemokines, and cell markers, as well as diminished hemorrhage and edema, correlating with reduced clinical score. Administration of the liposomal formulation results in accumulation of BMS in the brains of sick mice but not of healthy mice. This steroidal nano-drug effectively eliminates the adverse effects of the cerebral syndrome even when the treatment is started at late stages of disease, in which disruption of the blood-brain barrier has occurred and mice show clear signs of neurological impairment. Overall, sequential treatment with nSSL-BMS and artemisone may be an efficacious and well-tolerated therapy for prevention of CM, elimination of parasites, and prevention of long-term cognitive damage.
    Full-text · Article · Aug 2013 · PLoS ONE
  • Shaher Duchi · Haim Ovadia · Elka Touitou
    [Show abstract] [Hide abstract] ABSTRACT: We investigated the efficiency of nasal drug administration as a new non-invasive treatment strategy for MS. Glatiramer Acetate (GA) and GA-Cannabidiol (CBD) combination administered in nasal delivery system (NDS) resulted in a statistically significant decrease of clinical scores and inflammatory cytokine expression in experimental autoimmune encephalomyelitis (EAE) mice. Even a suboptimal dose of Prednisolone in NDS was effective in preventing the clinical signs of the disease. Neuron regeneration was observed in the hippocampus of EAE mice treated with GA-CBD in NDS. This work shows that nasal administration improved drug efficiency and stimulates further research for a non-invasive strategy for MS.
    No preview · Article · Mar 2013 · Journal of neuroimmunology
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    Nir Erdinest · haim ovadia · Abraham Solomon
    [Show abstract] [Hide abstract] ABSTRACT: comMultipurpose solutions (MPSs) are the leading method for cleaning and disinfecting soft contact lenses (CLs). During recent years, numerous clinical studies have evaluated the MPS damage to the ocular surface. This study examined the cytotoxic and the inflammatory effects of MPSs and hydrogen peroxide disinfection system (H202) compared to appropriate controls on human corneal epithelial (HCE) cells. Primary cultured HCE cells were exposed to eight different commercially available MPS products (MPS A, ReNu MultiPlus®; MPS B, Opti Free® EverMoist; MPS C, Solo-care Aqua®; MPS-D, Complete®; MPS-E, Unica Sensitive®; MPS-F, Options Multi®; MPS-G, Biotrue®; MPS-H, COMPLETE® RevitaLens). Morphological changes and cytotoxic effects were examined with FITC-Annexin V/ PI and MTT assays. The protein contents of the inflammatory cytokines interleukin (IL)-1β, TNF-α, IL-6 and IL-8 were examined by multiplex fluorescent bead immunoassay (FBI), and the mRNA expression was examined by real time PCR. Lipopolysaccharide (LPS) with 500 ng/ml CD14 and 500 ng/ml LBP (LPS complex), polyinosinic: polycytidylic acid (Poly I:C) and un-neutralized H202 served as positive controls, respectively. Phosphate-buffered saline (PBS) was added as a negative control. The study demonstrated that most of the MPSs induced varying degrees of cytotoxicity to HCE cells, and increased production of pro-inflammatory cytokines compared to the negative control. In addition, several MPS increased the mRNA level of inhibitory factor-κBα (I-κBα). Among the various MPSs, MPS-H induced the highest protein contents of the pro-inflammatory cytokines (14.37±2.2-fold for TNF-α, 41.39±2.5-fold for IL-1β and 5.24±0.6-fold for IL-6) compared to the negative control (p<0.05). In contrast, no significant differences were noted between the neutralized H202 and the negative control. We conclude that most of the currently used MPSs induce significant damage and inflammatory response in corneal epithelial cells. MPS-induced inflammation was mediated through NF-κB signal transduction. This study demonstrates for the first time inflammatory responses at the molecular level in primary HCE cells following exposure to a large series of commercially available and commonly used MPSs. These findings strongly suggest that certain MPSs may be partially involved in the pathogenesis of contact lens intolerance. Therefore, we recommended that practitioners advise patients as to the preferable disinfecting contact lens solutions, and to consider using the hydrogen peroxide disinfection systems instead.
    Full-text · Article · Feb 2013 · European Journal of Inflammation
  • [Show abstract] [Hide abstract] ABSTRACT: Inflammatory demyelinative diseases of the central nervous system are mostly idiopathic and represent the major cause of neurological disability in young adults. These diseases differ in terms of clinical symptoms, severity, pathological characteristics and epidemiology. However, there are also significant similarities between these diseases, which sometimes bring to a misleading diagnosis. Neuromyelitis optica (NMO) is a demyelinative disease in which the optic nerve and the spinal cord are predominantly affected. The detection of specific antibodies to aquaporin-4 (NMO-IgG) led to a modification of the diagnostic criteria for NMO. We performed a retrospective study on NMO-IgG positive patients referred to the Department of Neurology MS Center (2006-2011) with suspected NMO. Based on the presenting symptomatology of the patients, we identified the cases with optic neuritis and various parameters that may differentiate between NMO and MS. NMO-IgG were evaluated by ELISA. A total of 50% of the 107 patients with NMO-IgG fulfilled the revised criteria of NMO; 38 patients had a single attack of optic neuritis or long lesion in the spinal cord and 15 patients presented with an opticospinal type of MS. The visual acuity following a single attack of optic neuritis remained significantly lower in NMO patients as compared to MS patients. Most of the NMO patients with NMO-IgG had additional attacks of optic neuritis within a short time from the initial event. The finding of NMO-IgG in patients with optic neuritis foreshadows a bad prognosis and relapses. These patients are at high risk of experiencing a second event in the central nervous system and fulfilling the clinical criteria for NMO. Due to the difference in the severity of inflammation of the optic nerve between NMO and MS, it is highly recommended to seek a laboratory check-up for NMO-IgG in serum, immediately after the first event, in order to determine the necessity and the kind of treatment for the patient.
    No preview · Article · Feb 2013 · Harefuah
  • Nir Erdinest · Haim Ovadia · Abraham Solomon
    [Show abstract] [Hide abstract] ABSTRACT: Multipurpose solutions (MPSs) are the leading method for cleaning and disinfecting soft contact lenses (CLs). During recent years, numerous clinical studies have evaluated the MPS damage to the ocular surface. This study examined the cytotoxic and the inflammatory effects of MPSs and hydrogen peroxide disinfection system (H202) compared to appropriate controls on human corneal epithelial (HCE) cells. Primary cultured HCE cells were exposed to eight different commercially available MPS products (MPS A, ReNu MultiPlus®; MPS B, Opti Free® EverMoist; MPS C, Solo-care Aqua®; MPS-D, Complete®; MPS-E, Unica Sensitive®; MPS-F, Options Multi®; MPS-G, Biotrue®; MPS-H, COMPLETE® RevitaLens). Morphological changes and cytotoxic effects were examined with FITC-Annexin V/ PI and MTT assays. The protein contents of the inflammatory cytokines interleukin (IL)-1β, TNF-α, IL-6 and IL-8 were examined by multiplex fluorescent bead immunoassay (FBI), and the mRNA expression was examined by real time PCR. Lipopolysaccharide (LPS) with 500 ng/ml CD14 and 500 ng/ml LBP (LPS complex), polyinosinic: polycytidylic acid (Poly I:C) and un-neutralized H202 served as positive controls, respectively. Phosphate-buffered saline (PBS) was added as a negative control. The study demonstrated that most of the MPSs induced varying degrees of cytotoxicity to HCE cells, and increased production of pro-inflammatory cytokines compared to the negative control. In addition, several MPS increased the mRNA level of inhibitory factor-κBα (I-κBα). Among the various MPSs, MPS-H induced the highest protein contents of the pro-inflammatory cytokines (14.37±2.2-fold for TNF-α, 41.39±2.5-fold for IL-1β and 5.24±0.6-fold for IL-6) compared to the negative control (p<0.05). In contrast, no significant differences were noted between the neutralized H202 and the negative control. We conclude that most of the currently used MPSs induce significant damage and inflammatory response in corneal epithelial cells. MPS-induced inflammation was mediated through NF-κB signal transduction. This study demonstrates for the first time inflammatory responses at the molecular level in primary HCE cells following exposure to a large series of commercially available and commonly used MPSs. These findings strongly suggest that certain MPSs may be partially involved in the pathogenesis of contact lens intolerance. Therefore, we recommend that practitioners advise patients as to the preferable disinfecting contact lens solutions, and to consider using the hydrogen peroxide disinfection systems instead.
    No preview · Article · Dec 2012 · Contact Lens & Anterior Eye
  • Haim Ovadia · Tali Siegal · Joseph Weidenfeld
    [Show abstract] [Hide abstract] ABSTRACT: Background: Central nervous system (CNS) irradiation has detrimental effects which become evident within hours to few days and after a long latency of months and years. However, the delayed effect of irradiation on neuroimmune diseases has not been thoroughly examined. Objectives: We evaluated the delayed effects of irradiation on the course of experimental autoimmune encephalomyelitis (EAE), which is used as a model for neuroimmune inflammation and multiple sclerosis. Methods: Adult male rats were exposed to a dose of 15 Gy given to the thoracolumbar spinal cord. Six months later, EAE was induced by inoculation of rat spinal cord homogenate in complete Freund's adjuvant (CFA). The disease was evaluated by clinical, histopathological and immunological parameters. Results: Irradiated rats developed clinical signs of EAE earlier than the control group and their disease was much more severe. Unlike the control group, all rats in the EAE-irradiated group died within 5 days after the onset of clinical signs. Sections taken from irradiated rats showed diffuse and large hemorrhagic infiltrates of lymphocytes and granulocytes. In contrast, control rats displayed fewer infiltrates, which were less prominent and not hemorrhagic. Conclusions: CNS irradiation has a delayed effect that caused a marked aggravation of the clinical and pathological signs of EAE. The severity of the disease may be a consequence of the effect of irradiation on the CNS vascular bed and impaired blood-brain barrier.
    No preview · Article · Nov 2012 · NeuroImmunoModulation

Publication Stats

4k Citations
515.36 Total Impact Points

Institutions

  • 1988-2007
    • Hebrew University of Jerusalem
      • Department of Neurobiology
      Yerushalayim, Jerusalem, Israel
  • 2006
    • Wageningen University
      Wageningen, Gelderland, Netherlands
  • 2005
    • AHEPA University Hospital
      Saloníki, Central Macedonia, Greece
  • 1991-2004
    • Hadassah Medical Center
      • Department of Neurology
      Yerushalayim, Jerusalem District, Israel